Hypermiling: Expert driving to save 25% on gas.

Actual stats while driving my gigantic 1999 Honda minivan. Over 30MPG over a 336 mile stretch with almost half a tank still left!

Who wants to spend less money on gas? Everyone? Yeah!

Every few weeks, you’ll see yet another simplistic article in a bland mass-market publication like USA today or CNN news that says the same things about saving fuel: pump up your tires to manufacturer recommendations, accelerate smoothly, combine errands, and so on. You already follow the tips, and you’re wondering if Mr. Money Mustache can offer you more. The answer is of course yes.

I’ve always been pretty  interested in maximizing my own car’s fuel efficiency. It’s a neat little numbers game, seeing how far you can get with each tank of gas, and as a result I have calculated the average MPG of pretty much every tank of gas I’ve ever bought since my first foray into motor vehicle ownership in 1990 (a 1984 Yamaha DT-125 dirt bike, approx. 45MPG US in mixed terrain of steep mud stunt ramps and cow patties).

But the hobby has really ramped up in recent years along with the increase in gas prices and my discovery of “hypermiling” as an entirely new sub-field in the Online Nerd community. I started reading articles on websites like CleanMPG.com and learned that I was not alone. After a year or two of careful consideration, I decided to up my game by ordering myself an UltraGauge engine monitor for $80*. This is a simple device that reads key data from your car’s engine computer and displays it on-screen. I use it to watch instantaneous and average MPG, gallons-per-hour stats, engine temperature, etc, all while experimenting with driving style.

Here’s the neat thing about fuel efficiency: it has a big impact on your bottom line, since the average US driver spends two thousand dollars on fuel per year.  But contrary to popular wisdom, it has two components: the car itself and THE DRIVER.

The Environmental Protection Agency tests and rates each new car model to figure out its fuel consumption in typical use. The funny part about their rating system is that they have to keep changing it because the average US person drives so inefficiently that they end up using even more fuel than the EPA estimates.

The typical sentiment among drivers is, “Oh, EPA estimates are so optimistic, you’ll never get that mileage in real life”. Among hypermilers, however, the opposite is true: “Thank goodness I don’t get those shitty mileage figures estimated by the EPA, or my gas bill would be ridiculous!”.

Case in Point: if I look up EPA estimates for my 2005 Scion xA here: http://www.fueleconomy.gov/feg/findacar.htm, it tells me I will get 27MPG city, 34MPG highway, averaged to 30. In reality, my average is about 44 city, 40 highway, and I’ve never ever seen anything below 33MPG – a tank used up with a lot of short cold-start trips during a brutally cold winter with snow on the road. Under ideal driving conditions (mild weather, no stop lights and choosing my own speed), the car gets about 52MPG.

Similarly, my 1999 Honda Odyssey construction van is rated at 16 city, 23 highway, averaged to 19, while I have averaged 27MPG in mixed driving, with high of 31MPG across over a thousand miles of 68MPH freeway driving and a low of 22.3 this summer with constant air-conditioning, city traffic, and plenty of hauling of 1500-lb loads of construction materials up the steep dirt road to the cottage.

My own averages correspond to about a 25% savings on fuel – even without any major changes to the vehicles. How do I get these amazing results that make the EPA estimates look utterly pessimistic?  While I just consider it “normal non-ridiculous driving”, you could also get nerdy and call it “hypermiling”, and this is how we do it:

1: City driving style.
Most people assume that their car is getting “25MPG or whatever” for the duration of their driving. But the truth is much more exciting than that. When you’re accelerating away from a light, you’re getting about 9MPG and burning fuel at $15 per hour. When you’re coasting, you are getting 60-100 MPG. If you are accelerating half the time, and manage to coast the other half, you’ll still average under 18MPG in this situation. So you need to coast more than half the time.. the opposite of one of my friends who is always either using gas or brake.

When you are idling at a light, you are burning from 60 cents of fuel per hour in a tiny car, to $1.80 per hour in a large one. So while idling is always unpleasant, a much bigger factor in your fuel use is how and when you do your acceleration.

A good guideline to make you think carefully about acceleration is this rhyme I’ve made for you:

“If you have to brake, you’ve made a mistake”.

Obviously this is an exaggeration – other drivers, safety concerns and obeying traffic laws will provide plenty of reasons to hit the brakes.. but still if you think braking is bad, you will start planning your acceleration much more carefully. And you’ll avoid driving in high-traffic areas in the first place, because you should be biking or doing  the car errand later that night when traffic clears.

Overall, you should still use your brakes, but pretend they are hooked up to a speaker on your dashboard which blares out my voice saying “MEEEEEEEHHHHHHHHHH!!!” at you for the duration of your brake application – each and every time you touch that pedal. Pleasant, isn’t it?

And when you are damned with the chore of driving in traffic, you can still improve things by watching the traffic ahead of you – not just the guy in front, but the next ten cars, and the bikes and pedestrians, and the traffic lights and side streets. “That lady two cars up there keeps looking to her left – she is trying to find an address, leave her extra space. That guy just hopped on his bike and is looking the wrong way.. he will end up crossing in front of me”.  The benefit of all this hyper-focus is that it also makes you much safer on the road. I never talk on the phone or comb my mustache in the rearview mirror in city traffic – there is much more important work to be done.

2: Highway driving style.
Your car gets its best fuel economy somewhere between 25 and 65 MPH. It varies widely based on engine size and transmission type, but it is safe to say that you are always wasting plenty of gas (at least 15% over peak fuel efficiency) if you get all the way up to 75MPH. Of course, if you are seriously in a rush it may make sense to burn the extra gas (on cross-country roadtrips with multiple people I always go at least this fast, because the extra cost is small compared to the collective benefit of everyone getting there faster). But when you are going 75, you should always have this song playing in your head:
“I am Mister Fancy, I am in a hurry, my time is so valuable that I am wasting gas. Wasting gas, wasting gas, look out world I’m wasting gas. Tomorrow I will save some gas, but today I’m wasting gas”. If you do not like my song, you can substitute “Mrs”. for “Mister” above, or even write your own and send it in.

At least 50% of your highway fuel is being used to push air out of the way. You can cut your wind load significantly by simply drafting behind a transport truck. I find that if I hang back at a very safe distance – two seconds of road space, so that the truck trailer looks about 1.5x bigger than my thumb held at arm’s length, my fuel efficiency instantly jumps by 20%. While crossing the country in my van, this trick saves me about $20 of fuel per driving day. You can get bigger savings by drafting closer, but only if you enjoy danger – logically it is not worth risking a crash for an extra $1-$2 per hour of fuel savings. At the safe distance, however, the ride is nice. Truckers are expert drivers and they move consistently and anticipate road conditions well in advance.

3: Engines waste gas when they are cold
When a car first starts, the engine is cold. I found that for the first several minutes, the fuel consumption for light driving is actually double what it would be with a warm engine. The idle fuel consumption in my Scion is 0.39 gallons per hour when cold, but only 0.15 GPH when warm. A similar effect occurs during acceleration. So people who use cars incorrectly for bike-compatible errands are effectively paying $8 per gallon for their gas. To avoid this, you simply use your car only for major trips, or at least consolidate errands so the engine stays warm between them. Avoiding constant hot/cold cycles is also part of my secret to keeping cars healthy for 20+ year lifespans.

4: Engines are most efficient under fairly high throttle at low RPMs
Have you ever heard of “Pulse and Glide”? It’s a counterintuitive trick used by hypermilers when breaking world efficiency records. They put the car in its highest gear, and accelerate up to highway speed. Then they put the car in neutral (or even turn it off) to coast down to a moderately low speed. Repeating this up/down cycle actually uses less gas than rolling along at an intermediate speed, because the engine is more efficient when working harder for short intervals, than it is working lightly forever.

This is also why cars with less powerful engines tend to have higher fuel efficiency even if all other factors are equal – because the small engine is working in a more efficient part of its power range during typical driving. In real life, you can take advantage of this fact by keeping your car in the highest gear possible for the situation. And always ordering the smallest engine possible – never the V8 or V6 option, since even the smallest and least powerful car in the US is still ridiculously fast.

5: Coasting in neutral saves only a little bit of gas, and only on certain hills.
If you go down a hill and put the car in neutral, you are using only the power needed to idle the engine. Pretty good, since at 60MPH a midsized car will get about 200MPG in this situation.

If you leave your car in gear, and take your foot off the gas at high speed, you are actually using ZERO fuel. This is because the car detects that no fuel is needed to keep the engine running (the wheels are turning it via the transmission) so it cuts off the injectors completely. This saves between 0.15 and 0.5 gallons per hour depending on engine size, which is significant if you do a lot of coasting as I do.

Now, the neutral coaster will end up coasting further and faster than the in-gear coaster, because coasting in gear sucks up lots of energy (which is also known as “engine braking”). So on a long, gentle hill where you need to be in neutral to maintain speed, you save fuel by being in neutral. On a steeper hill like a mountain road where the engine braking is actually useful, you will use less gas being in gear. But overall, we are talking fairly small amounts of fuel of less than $1 per hour of coasting  – not worth fretting or risking safety over. I still coast in neutral on remote country roads because it is fun, even in the automatic transmission van, but not in the city or the mountains. In the manual-transmission car, I use neutral much more often in city driving, since going to neutral is instantaneous in a manual. In this case, there are many times you want maximum coasting distance with zero engine braking.

6: When should I turn off my engine?
Always. As noted above, you are wasting $0.60 to $1.80 in fuel per hour of idling, and you save fuel by shutting off the engine for any event longer than ten seconds. So, no idling in the parking lot while someone runs into the store, no idling in the drive through (actually, no drive throughs at all, as they are a stupid invention), and if you get stopped for a train or a ridiculously long traffic light, you can even shut off the engine for that. Of course, it’s only 3-9 cents of fuel to idle for a three-minute light, and it is surely a bad idea to pull this stunt in front of a police car, but sometimes the joy of just sitting in a silent car wasting zero gas at the longest light in history is worth the effort. Someday, I’ll have an electric car or hybrid so this happens automatically.

7: How much does air conditioning really cost to use? What about headlights and other accessories?  Thanks to the Ultra Gauge, I was able to test all these things directly while idling for a minute when the engine happened to be at full operating temperature.

In my van, which has a princely dual-zone system designed to cool seven passengers, the  A/C boosts the fuel consumption at idle from 0.49 GPH to 0.74 GPH. So it is burning 0.25 GPH, which is $1 per hour at $4 per gallon. When driving 65MPH, this same van normally uses $8 per hour of fuel, so the air conditioning is sapping a surprising 12% of the fuel efficiency – about 3.5 MPG. But it’s best to just think of the hourly figure, so you can decide “Is it dollar-an-hour hot in here today, or not?”

In my small car, the figure is only half as much – 0.12 GPH or 50 cents per hour. In moderate weather, the tradeoff speed between opening windows and running the air conditioning is about 50 MPH – use the A/C if traveling faster than that, unless one of your passengers needs access to the roaring air to do cool hand stunts.

Headlights are a much smaller drain – adding only 0.02 GPH (8 cents per hour) to the toll. The radio was even lower, not even registering on the 0.01 GPH-increment scale unless you are rattling the license plate with competition-grade subwoofers and amps at high volume.

8: Vehicle Modifications, small and large
You can reduce your car’s rolling resistance,  make it lighter, make it more aerodynamic, and make the engine more efficient, in that order of difficulty.

Rolling resistance is caused by the tires. The harder the tires, the lower the rolling resistance. Automakers specify a fairly low pressure, like 30 PSI, to balance fuel economy with the mushy ride most US drivers expect, but I find that you get a firmer ride with sharper handling and higher efficiency by using the maximum pressure specified on the sidewall of the tires itself – I use 40 PSI, close to the 44PSI rating of my current tires. This change yields about a 2% increase in fuel efficiency. Next time you replace your tires, you can also select “low rolling resistance” models that add 2% or more to a regular tire’s performance as well.

In a 3,000 pound car, each 30 pounds you slice from the weight cuts your weight by 1% and increases your fuel efficiency by about the same amount. It also improves acceleration and handling. I always start by removing the spare tire, jack, and related metal accessories from the trunk. There’s 50 pounds, and a bunch more trunk space. I do add in a can of fix-a-flat tire repair spray. Spare tires are good if you’re traveling alone through Death Valley or South America, but for local errands, in a world with cell phones and internet access, I haven’t worried one bit about my own habit of never carrying spares for the past 20 years (I have had a few flat tires over the years, but always just slow leaks that I discovered in my driveway – an embedded nail or similar).

Taking out unneeded seats in a van, trailer hitches or other cargo is also useful for a small boost. A full tank of gas at 8 pounds per gallon usually weighs over a hundred pounds too. Because of this, and because a full tank of gas lasts several months in my van (raising concerns about spoilage), I usually buy only a quarter or half a tank unless I’m heading out on a road trip.

Aerodynamics are hard to change for the casual fuel-saver. You should definitely keep all roof racks off of your car except when actually using them on a trip – a typical rack wastes over $100 per year of fuel, but other than that there are not many easy ones to do.

Enthusiasts, however, buy sheets of Coroplast plastic and attach them firmly to the underbelly of the car and over the rear wheel wells. These two things can significantly improve highway efficiency, although I have not had the motivation to go this far myself. Hypermilers also block at least part of the intake grille on the front of the car, which I have done. This improves aerodynamics and lets the engine run warmer – which sounds bad but is actually good in most cases if you read up on it. As a final trick, I sometimes flip in one or both of my external rearview mirrors when driving extremely long distances in extremely remote areas (for example crossing Wyoming at night). I can still see outside just fine with the internal rearview and my usual shoulder checks for lane changing. At high speeds, this saves a surprising amount of fuel – 2%.

The Final Factors: Minimal Driving and Vehicle choice:

The tips above will help an EPA-level driver slice their fuel costs by 25% without replacing their car or changing their driving habits. But of course we will go much further than that, since my own goal for you is to have transportation costs at least 75% below normal. To get to that level, you need to use a reasonable car and drive less, being sure to live within 10 miles of work, and bike or walk there most of the time. These are the most important factors, but they are rarely mentioned in newspaper and magazine guides, because the publishers don’t want to offend anyone (or may not even realize themselves that lifestyle change is possible).

For anything other than massive family roadtrips or heavy load hauling, you should be driving a lightweight 4-cylinder vehicle with manual transmission. EPA rating of 25 or better in the city, 32 or better on the highway. If not, you’ve used excusitis to incorrectly justify getting yourself the wrong car. This may sound tough to you now, but as your frugality muscles become stronger it will become an easy choice.

There are several hypermilers among the readers who are much more badass than me at the sport. We will probably hear from them in the comments. Hopefully their tricks and mine above will save all of you many gallons in the years to come, until we all finally switch to electric cars!

* Shame on the Ultragauge company: Don’t be fooled by the misleading $59.95 price sticker.  This device costs $80. (it is $69.95 plus about $10 of shipping, and there is a super-inconvenient mail-in rebate that actually requires you to do a test to get the refund. Even I didn’t bother to mail it in, as the time required worked out to a very low hourly return on the effort.)  This is misleading, and the company deserves to suffer for it. But even thought the Ultragauge has a very crude and unpolished interface, and is expensive for something simpler than a wristwatch, it is still better and less costly than the ultra-pricey ScanGauge.


  • GL July 26, 2011, 7:32 am

    ” you save fuel by shutting off the engine for any event longer than ten seconds”

    I’ll be the first to admit I’m a dummy when it comes to cars, but I always thought that frequently turning your engine on and off can damage it. O_o Is that an urban myth, or is there some truth to it? If it’s the latter, then saving those 3-9 cents per traffic light won’t be nearly enough to replace your engine…

    • MMM July 26, 2011, 8:10 am

      It won’t damage the engine, but it will wear out the starter motor more quickly. This may or may not actually matter, since the starter motor still outlasts the car in many cases. If not, I just looked it up and that component costs $81 for my car.

      The US delivery companies UPS and FedEx have started turning off their trucks during deliveries, and they did factor in more frequent starter motor replacements and still came up with a savings.

      But as I mentioned in the article, I still don’t recommend turning off your car at a traffic light as a significant savings to readers because the savings are pretty small, and you do run the risk of breaking the law or holding up traffic if you are slow to get it restarted for the green. But I still do it myself more for psychological reasons.

      For parking lots and waiting for people, however, I definitely recommend turning off the car for everyone, just because people who idle their cars in these situations are inconsiderate douchebags. Avoiding douchebaggery is always worthwhile.

      • Bakari July 26, 2011, 5:13 pm

        There is a small amount of additional engine wear from each start because it takes a second for oil pressure to build up. I don’t know how small it is, but I think the 2 grand I save a year on fuel costs should more than pay for the cost of a rebuild that is required in, say, 5 years instead of 10.

        As to the starter motor, the ones you buy at Chain Auto Parts Store come with lifetime warranties, so no matter how many you wear out, you only have to buy the first one.

        • turboseize February 18, 2013, 12:09 pm

          Be very careful about turning the car off – that is, if it is turbocharged.
          ALWAYS let a turbocharged car cool down and idle for at least 30 seconds before switching it off.
          The duration necessary for cooling down and idling depends on how hard the car was driven, and whether the turbocharger is watercooled or oilcooled only.
          For example, a turbocharged petrol engine with an oilcooled turbocharger will leave the turbo glowing yellow at autobahn speeds. Glowing yellow means over 900°C, if I remember correctly, which is way hotter than what any engine oil can cope with (oils start rapidly degrading chemically over 130-160°C). As long as the engine is running, that is absolutely no problem, as the oil is constantly pumped through the engine and is therefore leaving the turbocharger within fractions of a second, then get’s cooled down again in the oil cooler and the oil pan.
          When you turn the engine off, the oil pump also stalls, meaning whatever oil is in the turbo at this moment is going to stay there – and burn. Oil sludge and oil coal will build up in the bearings and even in the oil supply pipes, killing your turbocharger at a ridiculously low mileage.
          So gunning down the autobahn at full throttle, then breaking for the gas station, shutting off the engine and refuling ist not only wasting gas, but also killing your turbo. Unfortunately, this behaviour is quite common here, and people keep complaining about turbo failures…
          When driving hard (meaning not only speeding, but also driving uphill or towing heavy loads), always allow the turbo to cool down. Idling before shutting the engine off is better than nothing, but takes a lot of time: from “glowing” to “no longer visibly glowing” my old 900 turbo would need approx. 8 minutes. A much more effective strategy is to decelerate using engine breaking. This essentually pumps cold air though the engine, greatly helping to vent off excess heat. Then drive moderatly for about one or two kilometres, leave the engine idling for about 30 seconds before you turn it off, and the turbo should last for nearly forever.
          When driving at lower loads, the problem of course is not so severe. After moderate city driving, staying clear of boost and not exceeding 2500/min, letting the car idle for 20 to 30 seconds should be absolutely sufficient.

          Diesel engines have lower exhaust gas temperatures, meaning the problem ist not as severe. It is, however, still there. Even in a diesel the turbine greatly profits from NOT switching the engine off directly after having it work hard.

          Mustachians, of course, will drive consciously and thereby drive rather moderately, one might think. But they should also know how to let their equipmemt last as long as possible. Sacrificing the turbocharger for some cents of gas savings does not sound like a good deal to me.

          (A mustachian hypermiler could, however, count in the time the car is idling as he is coasting to a stop in neutral. ;-) )

      • Michael May 20, 2014, 8:35 pm

        In Seattle, their are signs posted all over the place that say: “Idling? Turn off the ignition.” (More easily seen on all the draw bridges.) With that, I don’t think it’s a law breaker over here.

      • Gannon January 29, 2020, 4:34 pm

        It’s also important to take into account the age and technology of your vehicle. A 2nd gen dodge ram, for example, is not one I would obsessively turn off and on. I’ve already replaced the starter once. $70 of starter can buy a lot of fuel at $2.38 a gallon.

        Also, if you daily a classic like my 72 dart, keep in mind where and how your power is being applied. I would reckon coasting in N will always be more efficient in a carbureted car, but I could be wrong. I don’t know when the tech of shutting off injectors was applied to consumer cars. Also, your electrical and cooling systems are much less efficient.

        Just like your “inflate tires” it pays to do some in depth research into your specific vehicle.

    • Dilt Wasney July 17, 2014, 10:39 am

      I don’t know about America, but here in Europe most new models are already factory fitted with start stop engines. That means that the engine automatically stops when the car stops for more than two seconds and it restarts immediately when you push the gas pedal.

      • Jenna Feeny January 16, 2015, 1:21 pm

        Nope. It is not a standard feature in the US yet. Most (if not all) hybrid vehicles and other cars billed as fuel efficient come with the auto-stop feature, but it’s far from standard. My hybrid (Honda CR-Z) has the feature and under most conditions, as long as the defrosters are off it shuts off in neutral once I coast below 20 MPH. You can buy aftermarket parts which enable you to shut off the engine, but I don’t know how that works since I assume it is more complicated than just turning the key.

        • Shaniqua January 28, 2016, 11:17 am

          I live in Alberta Canada. I just saw my first automobile that turns off and starts back up when idling for a few seconds. As my husband and I run a garage we discussed the wear and tear on the starter and battery. We could not draw any major conclusions as we have not seen enough of them as of yet.

  • Oskar July 26, 2011, 7:35 am

    Thanks for the tips. Once again I have to admit I am not as hard core as the mustache…but we try. We drive a 50 MPG Diesel Skoda station wagon which i guess is not sold in the US. A lot of engine power when needed and very good fuel economy. Our car is about 6 years old so it does not have all the fancy new stuff but the new versions of the same car has a start/stop system which atomatically shut of the engine when idle e.g. at a stop light. These systems are quite popular now at least in northern europe. We also have a electic heating system for the engine in winter, which warms the engine before driving and saves money and the environment with the addedn bonus of never having to clear windows in the morning when there is ice. Thanks for another great article.

    • MMM July 26, 2011, 8:05 am

      Again I am jealous of European cars! I’d love a diesel wagon, and a start/stop system for traffic lights is a nice way of getting some of the benefits of a hybrid without the complexity and cost.

      • Oskar July 26, 2011, 3:01 pm

        We will be going for improvement the next time, and with start-stop and a more efficient engine I think the next car we buy (in a few years) will get us over 60 MPG maybe 70 if we are lucky:-)

        In our current car we can easily travel with the whole family,2 adults and 2 kids (1 and 3 years old) and all we need for a vacation over serveral weeks (including stroler and travel bed for the little one). I don’t know how a ‘normal size’ family can ever need (to own) a bigger car.

        The only thing that got people to think about their car purchases in terms of fuel consumption here has been high gas prices (were i live a gallon is about 8 dollars) and I think it would have to double or tripple form that level before people realy start changing their driving habits. Right now people are driving as much as before but with more efficient cars.

      • qhartman October 31, 2011, 4:28 pm

        I have a diesel 2005 Passat wagon that I loooove, in no small part because it can happily run B99 Biodiesel, which is readily available where I live. If I were to do it over, I’d probably opt for the somewhat smaller and more efficient Jetta wagon instead.

        There may be a day coming where my family needs two cars, because we’ve moved out to the country. If/when that happens, I am undecided as to whether or not I will get a similar era diesel golf or bug to use as a daily driver, or an early 2000’s diesel pickup that can also run B99.

        I know the diesel vehicles aren’t always the most cost effective to run. The ones available in the US are relatively costly to repair and relatively fragile (relative to the Hondas of the world), and B99 costs enough more per gallon to negate some of the mileage gains. BUT, I get to know that I am sending zero dollars out of the country for my fuel while it’s warm enough to run B99, and that is something that you can’t put a price tag on.

    • Retinal September 10, 2012, 1:58 pm

      A 6-year old Skoda diesel station wagon? It is sold in the USA. It’s called a Volkwagen Jetta Wagon (now a Golf Wagon). They are essentially the same car as VAG (VW Auto Group) owns Audi, Skoda, Seat and Porsche.

      Not sure the engine size though… VW offers double the selection in diesel engines in Europe.

  • Heather July 26, 2011, 8:07 am

    Great article.
    A couple of questions:

    How long does it take your engine to warm up? (at ambient summer temperature). Is it just until the temperature gauge stops climbing, or some sooner point?.

    “In a 3,000 pound car, each 30 pounds you slice from the weight cuts your weight by 1% and increases your fuel efficiency by about the same amount.” I thought wind resistance was a greater factor than weight, in fuel efficiency. But that would mean getting much less than 1% back for a 1% weight difference. Perhaps it depends so much on terrain and stops/starts that it’s not easy to be precise. On a long road trip with few stops though, is weight a big factor?

    • MMM July 26, 2011, 8:38 am

      Good Questions, Heather! … My own engines both run at about 190 degrees fahrenheit, and they reach this temperature in 7-10 minutes in the summer (warm-up time is faster if you are at high engine output, like on a major road, and slower if you are just idling through the suburbs).

      An interesting note: engine temperature is so important to efficiency that the Toyota Prius (even the 2004 version) has an insulated thermos bottle in the engine where it stores hot coolant when you’re parked. This way, you keep a hot engine for more of a typical multi-errand driving day. I do believe that using an engine block heater to warm up your engine an hour before departure would end up saving more gas than it costs in electricity, but I have not yet done this test.

      Regarding the weight: In serious stop/start traffic, almost all the power is going into accelerating the car’s weight, and then being sunk into the brakes. The remaining power goes into overcoming rolling resistance of the wheels, which is directly proportional to weight. Aerodynamic loss in the city is pretty small – which is why Prius drivers and hypermilers get better mileage in the city. So weight is what matters.. and most people do a lot of stop-and-start in US driving. On the highway, rolling resistance is 50% of your energy loss, and aerodynamics are the other 50%. So weight is still really important. But you are still right – subtracting 1% of vehicle weight in a 50/50 mix of city and highway fuel consumption might really only save 0.8% of net fuel. But if you add in tire, engine wear, and brake savings, you might still get back to 1%. It’s an inexact science for the average driver – perhaps best at first to just get excited about saving fuel rather than sweating the details.

  • Lisa Marrin July 26, 2011, 8:49 am

    LOVE your article MMM, but must disagree.When you have three kids in carseats, drive-thru’s are the GREATEST INVENTION IN THE WORLD! I

    Keep on savin’!

    • MMM July 26, 2011, 10:16 am

      Drive-through grocery stores, if they existed. But drive-through food is unnecessary for Mustachians since we cook at home, and drive-through banking is silly since we have auto-deposit for our paychecks and we don’t have any use for paper money. (even if you do, just pay with a debit card and select “cash back” on those rare occasions you find yourself in a store).

      • Lisa Marrin July 26, 2011, 7:08 pm

        We have drive thru pharmacies and drive thru Dairy Barns…pretty handy. Not a fan of fast food but REALLY wish someone would open a drive thru pizza. Thats one dish I love to take out.

      • Belcat February 3, 2012, 1:04 pm

        We have “car delivery” grocery store; you just tell the cashier you’re doing a car delivery and she puts it in bins and rolls it down to the guy who’ll dump it into your car. They are phasing them out though… a casualty of people always wanting lower prices.

        I think drive-through results in slower service, and an annoying machine you have to talk to. If there’s any lineup I often prefer to get out and order, it seems faster and more natural.

      • Emma June 29, 2015, 6:38 am

        OK, I know this is a very very old article, but in the UK, we actually have something that operates a little like a drive through grocery store.
        Online grocery shopping is getting a good reputation over here. You can compare prices directly and depending on the company you buy from, you can book a slot an hour – 3 hours big, for as little as £1. (For reference, petrol is £1.15/litre at the moment!) They usually have an indication of when a van was going to be close to you anyway, thus saving the environment and your pocket, since they charge less for those. This has the added benefit of being able to purchase food in bulk sizes, because you won’t be the one paying for the transport of the thing, outside the standard delivery charge.

        For people who don’t want to pay the delivery charge, or who drive past a supermarket anyway, an increasing number of supermarkets have a ‘click and collect’ service. You arrive and someone else has done all your shopping and you just confirm payment and load it up. It means that you can pick it up on the way back from work, if you are short on time.

        We don’t have drive through banks or pharmacies- how ridiculous!. In fact most of our town centres have large pedestrianised areas and are only accessible via public transport/bicycle/walking from an out of the way car park But drive through grocery shopping, now that is something worth doing!

      • Ally August 20, 2019, 6:31 pm

        8 years later and we DO have drive-through grocery stores! Walmart now has free pickups for orders over $30. It might not be the best since they’re definitely not a local grocery store but it sure is nice to order online and only have to spend 10 minutes at the store. I’m much less tempted to buy extra things when I’m not going inside.

        Curious what MMM thinks about this new feature.

        • Mr. Money Mustache August 21, 2019, 1:59 pm

          I like it a lot! You are leveraging the efficiency (and to be honest low hourly wages) of the store employees to do the picking work for you.

          You can make it an even bigger win by biking to the grocery store to grab these nice bundles of pre-selected groceries though, tossing them into your bike trailer. In fact I have done exactly this with my local Sam’s Club.

    • sea March 12, 2016, 5:57 pm

      When my daughter took naps in the carseat – oh yes I used drivethrus! I didn’t use them before or since, though, just when I didn’t want to wake a sleeping baby. With a new baby on the way, I expect I’ll be taking advantage of them again though, for a couple years. :)

  • Jenny July 26, 2011, 10:01 am

    You know, Matt was really into this with our Scion xA too – he made it a game and had so much fun with it – he’s continued this now that we have the Prius too. At his high, he was getting 45-50mpg in the scion (I’ll have to ask him). And I agree with you on the Odyssey too – we get consistently in the mid 20’s with ours. I will pass this on though – it really does help! Mostly, it also changes your mindset while driving, let the landscape do the work for you, and relax and no rushing at lights or when you get to lights or slow down – and anticipate what’s coming. It’s a nicer way to drive – although I do hate it when I’m coasting because I see slower traffic ahead and someone rushes in that space that I have allowed because I’m not tailgating. Ugh!

  • Kevin M July 26, 2011, 11:18 am

    Good info, MMM. I currently get about 19 mpg average with my Jeep Cherokee. It is basically a big box – not very aerodynamic! I think the highest I’ve gotten on a tank is about 21 – lots of highway, no A/C or heat. We had a Prius as a rental a couple years ago and it was fun to watch the mpg screen as we drove. It would be cool if every car had this as a standard feature – I was definitely more conscious of my driving.

    • MMM July 27, 2011, 4:07 pm

      A Jeep Cherokee! Such an un-Mustachian vehicle for such a high-ranking MMM reader! ;-)

      Those Jeeps and other SUVs are amazingly inefficient – lots of the loss is built right into the engine – high-displacement, often coupled to an unusually lossy automatic. Then you combine it with relatively high weight and tall-tread, spongy tires. And there is very little benefit – a Subaru Legacy Wagon (or the even bigger Forester) has more interior space, 28+MPG fuel efficency, greater safety, drastically better handling, quieter ride, more refined interior materials, and the Outback version can still off-road like a MoFo. And you can get it with a manual transmission.

      • Kevin M July 28, 2011, 10:33 am

        I know, I know. I bought it 10 years ago and it’s paid off (very-Mustachian!) so I will hang on to it until it dies – only at 178k miles, going for 250k. My wife and I try to trade cars as much as possible, so I’m commuting in the smaller car. But I still think of the Jeep as “my car”. We’ll probably go with something like you suggest to replace it although the Subarus seem to be pretty pricey compared to similar models, maybe for the reasons you mention.

        • MMM July 28, 2011, 2:03 pm

          Haha.. I like the old car philosophy. Just remember that your jeep will burn about $15,000 of gas between now and that proposed 250,000 mile death, whereas you can replace it now with an older civic and keep $7500 of that money for your own ‘stash since the civic burns only half the gas. Every car owner should “do the math” on their own cars regularly, since it is usually very profitable to switch to an economical car instead of keeping a bad one just because you happened to already have it. I actually sold my 2004 Subaru impreza to buy the current Scion because 28MPG was still too gas-guzzling for me. 3 years later, I am very happy with this decision.

          • Fyl July 26, 2015, 4:22 pm

            28mpg is eye-wateringly bad…. My ’96 automatic BMW 328i gets hits 33.6mpg highway on cruise control’d 65mph (albeit, only on good fuel)

            And its modest-looking numbers – by today’s standards – hide a wolf in sheep’s clothing. Its 189bhp aren’t an unreachable redline peak on a distorted power curve, but actually available momentarily just by punching it…and its torque is not only a good 50% higher than similar a horsepower modern offerings, but furthermore comes in FULL strength and plateaus out just after 2000rpm – vs the nearly unreachable redline everests of modern engines.

            0.31 drag coefficient too…sole weakness? Seductively stompworthy throttle just begging you to pound her.

            And way more reliable and safer than the 2015 Nissan Altima rental that’a currently trying its best to jinx my cross country trip and just maybe kill me in the process…

  • CeridianMN July 26, 2011, 11:26 am

    Regarding engine temp and fuel efficiency. Living in Minnesota I have often in the past (not as much with the newer cars) started the car and let it warm up some before heading out. since the car uses much less fule while idling versus accelerating, and fuel efficiency changes with temperature for both, does it end up saving money to warm the car up at idle instead of starting it and running off?

    • MMM July 27, 2011, 4:01 pm

      No, according to the fuel efficiency experts, it does not save fuel to warm up your car by idling it. The best strategy is just to start it and start driving moderately. The engine will warm up more quickly if you are using it for actually driving – either way, the same amount of energy will be lost in warming up the engine, then it will become more efficient (although it will always burn more gas in very low temperatures – apparently because of cool intake air sucking energy out of the combustion reaction?).

      Using your garage if you have one, on the other hand, does save lots of fuel in winter. Especially if it’s an attached garage and you insulate it so it is less cold. My own garage never drops below about 45F in winter, even with no heating ducts from the house, so my car is never frozen, and it is much closer to operating temperature than it would be if I left it on the driveway (night time temperatures in January where I live are usually below 20F despite days in the 40s).

      • Bakari July 27, 2011, 4:53 pm

        There are aftermarket block heaters that can pre-warm an engine using electricity

    • jonathan January 14, 2016, 1:28 am

      You get 0 MPG idling and the engine it takes longer to warm up.
      Drive off straight away gently getting low MPG (better than 0 MPG) but increasing rapidly due to the increased fuel burn
      .5 gallon per hour idling 4 minutes 0 miles v 1 minute 2 gallons hour at 60MPH =1 mile traveled. Times 100 trips 100 miles extra +300 minutes 5 hours to do something more interesting than sitting in your drive way

  • Algis Tamosaitis July 26, 2011, 11:33 am

    I don’t own a car, but I do sometimes drive my girlfriend’s car to take her daughter to school and run errands. Heck, I’ve even been known to rent a car occasionally.

    Really enjoyed this article.

  • Sorbet July 26, 2011, 11:36 am

    It puzzles me that some (most?) drivers consistently over-accelerate and then slam on the brakes. It’s wasteful, not very zen and usually dangerous: in my experience it seems it’s often these drivers who are not anticipating what’s coming up and/or tailgating while talking on their cells.

    I don’t consider myself a hypermiler but I rarely need to use the brakes (as in I once drove a [sexy] classic car with catastrophically faulty brakes for a roundtrip without noticing anything). Once situation I will prefer brakes over coasting is if I anticipate a red light will turn green before I get to it if I brake first, then coast, instead of just coasting. I figure it saves the fuel and wear-and-tear of 0-30KMH in 1st gear. More experience drivers please correct me if I’m wrong :>

    • Bakari July 27, 2011, 4:54 pm

      You are correct about slowing in order to avoid having to stop completely at a light. The same goes for stop and go traffic.
      The crazy thing about over-accelerating and then having to brake is, it doesn’t even get you where you are going faster! At least with speeding you save a few seconds, but if you are going to have to brake anyway, you waste gas and increase risk while saving zero seconds!

  • Heather July 26, 2011, 12:38 pm

    I am Mrs Smarty
    Going to a party
    Some people like to be on time
    But tardy is more arty

    I am Ms successful
    Being late is stressful
    Driving fast I won’t be last
    But now my tank is lessfull

    • Moxie July 31, 2011, 12:55 pm


  • PNW July 26, 2011, 3:12 pm

    Good article. I’ve used many of these tips over the last several years and I consistently see 10-25% mpg better than the EPA estimates. I feel that many Americans drive vehicles too large for their practical needs. A econo car or scooter are usually more than enough for people that are not able to bike to work/store/etc.

    One thing not mentioned is that several older cars transmissions (possibly newer) wear prematurely if cruising at higher speeds in neutral. I believe it is due to the transmission not lubricating itself in neutral, or the trans lubrication system not working at the same capacity as when in gear.

    It’s also worthy to note that a cars power steering and brakes will no longer be power assisted if the engine is turned off. This can create an unsafe driving environment if the drive is not prepared for this change in steering and braking performance.

    Making an engine more efficient is not necessarily the most difficult option. Many drivers fail to do engine tune-ups on schedule. A dirty air filter, or spark plugs can effect the engines efficiency significantly. A cheap fuel injector cleaner (I’ve used one from Lucas Automotive) can also help improve mpg. On the more expensive side of vehicle modifications are installing lighter weight wheels. I have two sets of wheels for my car and one set, even with high grip winter tires, is lighter weight and give me 2-3 mpg highway over the heavier summer wheel/tire set.

    I’m going to tint my cars windows soon to help keep canine passengers cooler, perhaps enough that I won’t need to use the A/C nearly as much.

    Doesn’t aerodynamic loss increase with speed? It’s not always 50/50 on the highway is it?

    MMM, could you address the idea of using lower octane gas vs. higher octane gas?

    I’ve often turned off the AC when climbing hills or accelerating. Any thoughts if the AC uses more gas when the engine is under heavy load? Or is it even use despite engine load?

    • Bakari July 27, 2011, 5:02 pm

      Most automatic transmissions (including new ones) can be damaged from coasting in neutral IF the engine is off. Manual transmissions (of any age) just sit in an oil bath, there is no pump, so there is no difference if engine is on or off.
      I have never heard anything about problems from coasting in neutral as long as the engine is on.

      Its true that its important to realize the steering / brake feel will change with the engine off, but the brake booster usually has enough vacuum for at least one hard brake, maybe two (and if you are hypermiling correctly, you shouldn’t ever need to brake hard) and the steering is actually really easy without assist at highway speeds. One solution to the change in feel is just to remove the power steering fluid (and if the belt routing allows it, the entire pump). Its actually much easier than it sounds.
      While one is at it, they can remove the A/C as well.
      I not only tinted the windows, I also painted the roof reflective silver. Also, add beaded seat covers, and a 12v fan, and you are set.

      Yes, aerodynamic loss increases with speed. In fact, it increases exponentially, so if you increase speed by a factor of 2, the resistance goes up by a factor of 4.

      Octane is just resistance to premature explosion, unless you have a high compression ratio engine (mainly sports cars), you will see zero improvement from using high octane fuel.

      I have no idea about A/C at different loads (since I just never use it at all), I’ll leave that one to MMM

      • turboseize December 17, 2011, 9:34 am

        Higher octane rating allows for a more aggressive earlyer timing. This makes the engine more efficient, leading to more power or less fuel consumption.
        Obviously this magic only takes place if your engine management system is smart enough. Modern engine management systems use knock sensors to determine engine knock and will retard timing in case knock occurs. So low-octane gas won’t damage the engine, but give worse fuel economy.
        For best efficiency, use fuel with the octane rating recommend by the manufacturer.
        If you use even better, high-octane fuel, your engine management system should advance timing, giving you even better performance and economy.
        However, not every car is smart enough for that. I recommend you find a car freak who can extract and read engine maps…
        If your car does not support timing advance to this degree, you cannot fully exploit the better fuel and end up paying extra. Even worse, you nutzte even experience worse fuel economy, as very-high-octane fuel typically has a slightly lower caloric value, that is it provides less energy per liter.
        With my own Saab 900 turbo, for example, which uses a knock sensor solely for adjusting maximum boost pressure, I will use high-octane fuel (98-102 octane) only when speeding or at the racetrack (renting a flat 4km from Nürburgring entry… I know, un-mustachian and frivolous decadence), as the car will allow much more boost pressure. In everyday driving, I use standard 95 octane, as higher octane fuel does’t advance ignition timing in my car and is therefore a waste of money.
        Staying with the same manufacturer for the example, on a late Saab 9000 with “trionic” engine management, higher octane will also get more timing advance, meaning higher efficiency. You could even rewrite the maps if you feel this might help…

        A naturally aspirated engine without knock sensors, as in most bread-and-butter cars of the 80s, would not see any gains but instead losses due to lower energy content of the better gas. Of course, you could unscrew the distributor then and advance timing manually, if you knew what you were doing…

        To sum it up: theoretically, high-octane gas can increase fuel economy. Whether it actually does depends on how smart your car is.

  • Mike July 26, 2011, 3:19 pm

    Great article. I am already driving smarter.
    Less braking.


  • Roger July 26, 2011, 4:12 pm

    MMM – Do hybrid vehicles make sense in terms of cost/benefit?

    • MMM July 27, 2011, 3:50 pm

      Hi Roger, great question!

      Almost certainly not when you are comparing new hybrid vehicles to comparable-quality gas vehicles. For example, Toyota Prius is a money loser vs. Toyota Corolla/Yaris or Scion XD, since the gas versions cost $10-15k less. It is hard to save 10k on gas when going from 35 to 50 MPG unless you drive several laps of the Earth per year. You’re better off investing the $10k savings and your annual dividends/returns will be greater than your gas savings. Especially since insurance and registration taxes are often higher on more expensive cars.

      But in the used market, it can make sense. Once the current used Japanese car crunch (caused by the tsunami slowing down factories) comes to an end, you will start seeing 2004+ Prius’ coming up for sale under $9k again. At that level, it probably will save even a moderate driver money compared to buying a comparable quality used car for, say, $7k. For light drivers who travel under 6,000 miles a year, however, the price of the car becomes ever more important. So you just get a 2000-2005 fuel efficient car and let it last you for 10 or more years.

      • April October 17, 2011, 3:46 pm

        My Prius rocks! You’ve said it before, but I’ll endorse it from an owner’s perspective: purchasing a 2004-2009 prius is a great move! I sold my SUV and purchased a 2008 Prius to replace it. Not only is it getting triple the MPG, but I’ve found I can fit just as much in my prius as I could in the SUV. All the seats fold down flat-even the passengers seat, so even if you need to pick up some 8 foot beams or a full size door, you can do it in your Prius with all the car doors securely closed. It can’t haul as much weight though, so if you aim to pick up 800SF of tile, rent the truck. The display in the 2008 will even show you when you are hypermiling, making it easy to see your energy usage without purchasing extra devices.

        For more info on hypermiling, take a look at http://www.priuschat.com

        • Bakari October 17, 2011, 4:15 pm

          “I’ve found I can fit just as much in my prius as I could in the SUV.”

          And yet somehow, in the United States, the Prius is considered a “compact” car!!

          • April October 24, 2011, 10:16 am

            Ironic, isn’t it!

          • Johonn February 14, 2012, 12:23 am

            Depends on what the “SUV” was…

  • Bakari July 26, 2011, 5:25 pm

    I am really impressed.
    This covered just about everything! And you put numbers to stuff (the dollars per hour) that I hadn’t heard before.
    You probably already know this, but for your readers, if anyone wants to go even more indepth, the largest and most active online community is probably ecomodder.com

    I am actually planning to make a hypermiling class in the next few months – and I am definitely stealing your rhyme “If you have to brake, you’ve made a mistake”
    That has to be the best line I have read on this blog.
    …well… it does have some stiff competition… I sure loved the bit about punching the clients of your short term loan business in the face…

    I do have one note: You said you only fill the tank partway. Which I assume means you are getting MPG readings off the UltraGauge.
    I use ScanGuage (basically the exact same thing, but a different brand) and I find it is off by up to +/-15% and changes every tank. The only reliable way to get tank average is by filling to the top, noting the odometer reading, then filling to the top again and seeing how many gallons you added to determine how many you used.

    Once you get around to making mods to the car, I wrote up an Instructable about what I did to get 100% better mileage (truck is rated for 15mpg, I get up to 31 with moderate loads)

    • MMM July 27, 2011, 3:41 pm

      Thanks Bakari! Glad you like the rhymes.

      I found that my Ultragauge was already accurate within about 2% out of the box – when averaging over several consecutive full tanks during my winter road trip. So I just adjusted the calibration setting by 2% and now it is pretty much dead-on. So now I don’t bother to tell the device when I do a partial fill-up. Only for full fill-ups, which I do on road trips – that way the “distance to empty” calculation will be right.

      • Bakari July 27, 2011, 5:05 pm

        I wonder if its our car, or the gauge (or possibly user error)

  • Mr. Frugal Toque July 27, 2011, 6:55 am

    I was listening to something else on the radio when I read this column, so my Fancy Pants song sounds a bit different.

    Driving down the freeway in my Es-Ca … Lade!
    Doing One Thirty because I just got … Paid!
    Blowing gallons out my exhaust … Pipe!
    Smell my fumes because they are … Ripe!
    Don’t care about no enviro – Ment!
    Don’t keep track of no dollars and – Cents!

    Fancy … Pants!
    Fancy … Pants!

  • Clyde July 28, 2011, 2:39 am

    I live in the UK and drive an 800cc, 54 bhp semi-automatic Smart diesel which delivers about 80mpg, although the official figures say 85.
    However, for the size of car (it’s a two-seater) I feel it should be doing far more than that – at least 100mpg.
    I’ll try some of the above techniques that I haven’t tried yet to see if it helps.

    • MMM July 28, 2011, 7:59 am

      Yeah, I am interested in the Smart cars as well, but also disappointed that they are not as fuel efficient as they look. Reading up on the specifications, however, it makes sense – the car still weighs 1600 pounds (only 33% less than less than my 5-seater Scion xA’s 2400 lbs), and it has a very high 0.38 drag coefficient (23% higher than the Scion’s 0.31). A pretty big frontal area as well. What you really want is a long, low car for fuel efficiency rather than a short tall one.

      In my mind, a diesel Scion with a very tall top gear and slightly better aerodynamics would be the best of all worlds.. probably 65+MPG US (78MPG measured in standard imperial gallons, remember the 20% difference in these two units).. and a nice roomy passenger compartment.

      • Bakari July 28, 2011, 8:53 am

        that’s why I really love this design:

        and hope it catches on enough for production costs to drop.
        It just makes so much sense, having it be long and narrow.
        For aerodynamics, and also for parking (4 of them to one standard parking space!) and, at least in CA, for traffic (its legal to drive in between lanes here)

      • Clyde July 30, 2011, 4:24 pm

        Good points that I hadn’t looked into. Drag being the biggest factor I would imagine, as most of the weight would come from the engine and running gear, etc, which would not change much from a 2 or 5 seater.
        The problem with a roomy interior is, of course, that if used, it just lowers efficiency further.

  • melissa July 31, 2011, 6:55 pm

    Hi! I just recently bought a car when I moved to Lyons to be between work (Boulder) and school (Fort Collins). When I first bought the car, I tried not to brake, but I wasn’t used to Colorado lights so I ended up slamming on the brakes at the yellows – until I realized people in Colorado don’t stop at yellows, or even reds sometimes. Doing that really took a hit on the Progessive Snapshot thing that evaluates your driving and gives you a discount if you are a good driver. They did not think I was a very good driver. I’m used to living in the city and riding my bike/taking the bus everywhere, so it is quite the transition to have to drive! So thanks for your tips because gas is about $300/month for me. WTF! That’s almost my rent!! Too bad I like Lyons so much. So until we get a bus down 66, I will be staying between 25 and 65mph and trying out all of your tricks. I work out with your wife so maybe we will meet in person some day.

  • poorplayer August 16, 2011, 7:35 pm

    I wonder what MMM thinks about scooters. I note he has owned motorcycles but I am guessing he does not regularly use them for commutes anymore. I find the gyrations of hyper-miling mildly obsessive, so when I went to look for an alternative to save gas, I turned to scooters.

    I live about 3 miles from my workplace and have most everything I need in a 5-mile radius, and since about 1991 or so have used a Yamaha Razz 50cc scooter for commuting and errands. I paid $600 for it used. I have found it to be a great compromise between walking/biking and driving. I don’t need a MC endorsement on my license; it gets 90MPG; costs $5/yr to insure; does about 30 MPH downhill (I could de-restrict it but don’t); needs next to no repairs. I recently sold it to upgrade to a 250cc scooter for longer rides and personal enjoyment (down to 65MPG), but I still see it around town being driven by the new owner. It’s a 1989 model and still running.

    On a recent trip to India (and in fact in most other parts of the world) I noted that scooters are standard transportation in urban areas. Now, while the average Westerner would be not only appalled, but frightened for her or his life while in average traffic in India, you routinely see 2-4 people on a 125cc scooter. Women in saris ride sidesaddle on them. Dealers deliver 20lb. propane to houses with them. I cannot for the life of me figure why scooters have not become more popular in this country, particularly in warmer states.

    I live in a cold-weather area in a “snow belt” region, so from mid-November to mid-March my scooting becomes spotty (as long as the pavement is dry and snow/ice free, I scoot), and then I drive the 1993 Saturn I got free from my sister-in-law (we also own a 2006 Ford Escape V6, paid off). I have found that, for me, a scooter has proven to be a serious money-saver over 20+ years that has bridged well the choice between car owning/driving and bicycling/walking. For the record, I also sometimes bike and occasionally walk to work, but again, for me, the scooter allows me to close the time gap, because walking or biking clearly takes more time to accomplish (45-minute walk v. 7 minute scoot. Sometime I cannot spare the time).

    My experience with scooters has been very good, both in terms of time saved (which, I hear, is sometimes money) and dollars saved, while using far less fuel. As for the safety factor, I found that you are probably no more nor less safe on a 50cc scooter than you are on a bicycle; safer in some ways because it forces you to obey traffic laws. There seems to be in this country some sort of cultural prejudice that resists scooters as a viable and economical form of transportation. It’s worked for me; it might work for you.

    • MMM August 16, 2011, 8:03 pm

      Excellent point, Poorplayer! Scooters are fantastic and I should start talking about them more. It is my own bicycle-centric mentality that has blinded me to scooters – because I bike every day and usually do so with the enthusiasm of a crazy dog (top speed at all times, jumping curbs and finding opportunities for flying whenever possible), I find it is quite a speedy method of transportation – and it takes care of the cardio half of my fitness program as well.

      But I’m trying to spread these ideas to a much broader audience and not everyone is ready to go directly from a lifetime of automatic-transmission sillymobiles like the Buick Enclave to a full-suspension mountain bike. So scooters are a perfect middle ground. You cut out the cost of urban driving, but it doesn’t take any physical effort. Less excuses not to drive a car, higher probability of success. Baby steps. Thanks for sharing!

    • Oh Yonghao April 25, 2014, 4:43 pm

      While living in Taiwan my wife and I would do costco runs on her 100cc scooter, I remember those rides with the groceries loaded on the floorboard and my legs up over them riding them like a big fat Harley. Our gas expenses were about $10 a month back then. We’ve contemplated getting a scooter here too and may very well do so. My wife doesn’t like to ride a bicycle near as much as I do and hits a top speed of 10mph rolling down a hill.

      One very neat thing is that many people in wheelchairs use scooters in Taiwan with a slight modification. They add a sidecar basically which is a platform with a third wheel and a ramp which can be lowered to get on and off. They can then continue to steer using the handle bars and control it just as anyone else could.

  • Kevin August 30, 2011, 10:49 am

    Loved your article.

    Talking about Smartcars, just be careful not to compare diesel with gasoline engines in terms of MPG. Diesel fuel has more energy stored in the chemical bonds than gasoline, so it’s not a like-for-like comparison.

    Scooters (where I live, anyway) tend to have two-stroke engines with very crude exhaust systems. Motorcycles, too, have none of the advanced exhaust treatments that cars do. Yes, they are more fuel-efficient–smaller carbon footprint–than driving an SUV, but in terms of other pollution (unburned hydrocarbons, NOx, CO) they are *MUCH WORSE*. They are one of the reasons smog is so bad in some far east cities. Good article here: http://www.straightdope.com/columns/read/2852/whats-better-for-the-environment-a-scooter-or-a-car

    MMM Note – not true for new scooters, as strong EPA regs kicked in in 2010.. but since MMM readers are likely to by an old used scooter, this is still a good point.

    Also, just talking about speed, remember that wind resistance increases as a square of the speed, so the jump from 65mph to 70mph takes more gas than 60mph to 65mph.

    I’m off to buy myself a gauge. ;)

    • SteveT December 8, 2011, 3:03 pm

      Actually, comparing any two engines in terms of MPG is completely valid as long as you also include the price per gallon (PPG) of each engine’s fuel.

      The average person doesn’t care about the amount of energy contained in each molecule of fuel; they only care about how much it will cost them to use the engine.

  • tom December 6, 2011, 3:16 pm

    Thanks MMM; I loved the article.

    I was talking to a co-worker about having fix-a-flat instead of the spare/jack. He was concerned about possible damage that it could do to the tire. He suggested a tire-repair kit like this:

    I’d like to ditch the spare, does anybody have experience patching a tire after fix-a-flat?

    • Bakari December 7, 2011, 1:16 pm

      I don’t think you can patch after using fix-a-flat.
      You could still use a plug, if you can still find the hole (which seems unlikely)

      The official answer is you are supposed to use an internal patch AND a plug to consider it a permanent repair, however I have put thousands upon thousands of miles on van tires repaired with only fix-a-flat, as well as driven cross country and back in a car with a plug but no patch.

      Disclaimer: just because I have done it – and will continue to – doesn’t mean I recommend it. The can of fix-a-flat explicitly says it is not a permanent repair. (even though it is)


  • Phil F December 8, 2011, 12:34 pm

    For tall people, I can’t recommend the Yaris hatchback more. I’m over 6 feet, and my brother and I can take 600 mile road-trips to visit family and be comfortable the whole way. The car is tall, which gives great field-of-view over the nearby sedans, and the fold-down seat lets me treat it as a great storage vehicle with a fold-up seat for the once or twice a year I need to put more humans in it.

    It has power nothing (but brakes), which means easy and inexpensive repairs if and when they’re needed.

    All that and ~40MPG is chock full of Mustachian awesomeness.
    So unless someone is over 6’5″ or so, saying that they can’t fit in a fuel-efficient car is just whineypantsness.

    I love my Yaris…

  • SteveT December 8, 2011, 2:55 pm

    I realize the age of this article is great in Internet time, but I need to point out that when I was car shopping this spring, the EPA fuel estimates for a new Ford Focus showed higher MPGs for the automatic c.f. the manual transmission. When I asked about it, the reason given is that new automatics use a continuously variable transmission (CVT), and unless you are highly-skilled at changing gears to affect your fuel economy, the newest generation of CVTs are nearly impossible to beat. This makes sense since CVTs can access the perfect gear ratio to balance power demand with fuel conservation.

    Also, when I compared the fuel efficiency of a Subaru Impreza hatchback (not the fancy-pants WRX or STI variety) with a stock Jeep Patriot 4×4, the numbers were nearly identical (one was better in the city, while the other was better on the highway).

    • Bakari December 8, 2011, 6:38 pm

      That’s mostly true (I’m not sure you have to be “highly” skilled to beat it though, given how low the standards need to be for average)

      However, last I checked CVT were still only available on compact cars, due to their relative lack of strength.
      Of course, anyone reading this blog should be buying a compact car anyway, but if for some (ridiculous) reason someone wasn’t, they can’t assume they will be getting a CVT just because its an automatic

      • SteveT December 9, 2011, 1:32 pm

        CVTs are actually available on new SUVs and other vehicles. Jeep even makes a CVT-2L, a second-generation CVT that features 19:1 crawling gear.

        Before I learned the ways of the mustache, I went car shopping with the requirements that any new car I buy have some type of 4WD system (whether it was true 4WD or AWD), because I live in a city with terrible roads and plenty of bad weather. I also wanted a rear hatch. I decided to buy a Patriot instead of an Impreza because the aforementioned similarity in gas mileage.

  • Concojones February 4, 2012, 11:19 am

    Thanks for sharing your experience with us, MMM! I’ve never seen an article that makes saving fuel so beautifully simple as you just did. I’m taking away several good points here.

    What kind of tire pressure gauge do you recommend? (given that a cheap pencil gauge isn’t very accurate).

  • BC February 13, 2012, 6:30 pm

    I looked up your 2005 Scion xA on the fueleconomy.gov site, and the automatic transmission version, actually gets one more highway MPG than the manual version, however soon after in the article, you recommend getting a manual trans. I think these days, automatics (especially CVT’s) have gotten much more efficient, and driving style plays much more of a role in fuel economy. Sometimes (as in this case) a manual can actually be a hindrance to economy.

    • Bakari February 13, 2012, 7:06 pm

      The EPA ratings are based on a typical driver.
      You can go further above EPA with a manual, because there is much more technique available to you.
      With good driving technique a hypermiler can surpass EPA with a manual by anywhere from 30-100%, but even the best hypermiler can expect more like 10%-25%.
      With numbers like those, an extra 1mpg isn’t significant.

      • Hokiepat03 March 9, 2015, 6:50 pm

        What about a difference of 4 MPG for the 2015 Honda Fit CVT model? I’m trying to decide if the CVT is worth it in this case – that’s 10% better than EPA estimates and doesn’t require the level of constant attention of Hypermiling.

  • Scott March 10, 2012, 7:51 pm

    Great perspective, and I also enjoyed your articles on cost per mile and total cost of ownership. I try to convey these concepts to my friends, but they just stare blankly . . . and then counter that they can “afford” the monthly payments on their Bimmer leases.

    Of course, now they are all in tears since gas in Orange County CA is $4.60 per gallon (premium). I just cruise on by [smugly] at 55-60MPG in my paid off Prius :)

  • Cycling Sailor September 11, 2012, 8:19 am

    Dear MMM,
    In the A/C fuel consumption of your minivan, is there a typo or math error?
    0.64 GPH – 0.49 GPH = 0.15 GPH

    • Mr. Money Mustache September 11, 2012, 1:44 pm

      Thanks for the correction CS – it should have been 0.74 with AC on, so I changed it.

      I’m really amazed at how much that van uses for the dual-zone AC system. Then again, I guess the interior volume is about three times that of my smaller car, and there are vents everywhere, so it makes sense that it would need to run a much bigger compressor and more fans. Just another example of why smaller cars are better.

  • Cheryl October 8, 2012, 5:13 am

    I’ve been wondering about the neutral vs in gear rolling – If done right I can coast the last downhill to home in neutral and have enough momentum to make it down the hill, over the creek and up the next small slope to our corner at the right speed to shift into gear and up the hill. Plus it’s fun, there’s always the temptation to go “Wheeee!” on the way down.

    • jonathan January 14, 2016, 8:06 pm

      Fuel injected cars will shut the fuel off when the throttle is closed and back on when the revs drop to 600 -800 so the engine won’t stop.
      You can feel the slight jerk when you slow by just taking off the power and watching the tachometer.
      It was done with fuel injected engines as an emission control (no popping of late burning fuel in the muffler and no emissions and no fuel use)
      Easy to do with a a fuel injected all the hardware if in place it is just programming can also be done with common rail diesel engines.

  • Gordo December 12, 2012, 10:23 pm

    If you have an android phone, check out the free app called “torque”, you can buy a mini wireless bluetooth device (no battery required!) on ebay for $10 that will read just about anything that can be read from your car’s computer including fuel economy and much more (check engine light codes and O2 sensor readings/graphs for those that work on their cars).

    Search ebay for: mini elm327 bluetooth

    • John January 8, 2013, 11:39 pm

      I recently bought one myself, I especially like the heads-up display option if I’m driving at night, kinda makes me feel like I’m driving a luxury car. Just set the option and lay your phone on the dash, for those who haven’t used Torque. It really opens your eyes to mileage vs. driving habits, and is very wallet-friendly too.

      Very good article and comments! Maybe this will motivate me to do some mods to my Vibe.

      • Ellen January 27, 2015, 12:08 pm

        Hi! I see your comments were written in 2013. Are there any new items that you would suggest for 2015?

  • John January 8, 2013, 11:56 pm

    I am by no means a hypermiler, but have recently bought the bluetooth OBD2 adapter for my Torque app and have done a few minor mods to my Pontiac Vibe. I don’t know if they made much difference, but I disabled my DRL and with it, the automatic headlights (which were constantly turning on and off all day), and one mod I’ve not seen mentioned anywhere: the windshield defrost, on many modern cars, automatically activates the A/C compressor to dry the air, providing faster defogging of the windshield. My previous Saturn did not, and I rarely needed to activate the AC to defrost. I found that simply removing one wire from the defrost switch disabled this feature, now I can choose defrost with, or without A/C.

    I recently found an interesting side effect of effectively over-inflating the tires. I had been inflating them to a few PSI below the sidewall-stamped maximum pressure of 44, and the car recommends 35. When I had the tires rotated after way too many miles, the tire person said he was very surprised there was no odd wear on the tires and no tread damage caused by my blunder. I can only assume it is because the extra PSI prevented the tires from mis-shaping.

    Also, this is an excellent article with excellent comments. It is motivating me to strive to achieve hypermiler status.

  • Recent MMM Addict March 11, 2013, 1:05 pm

    Hi again! Still working through your past posts, and have a question about cars.

    I have 2 large dogs (one is over 90 pounds, and the other is over 110). My husband and I both drove small vehicles (Honda Civic for me – manual transmission, and a Honda Accord for him). When we decided to move from WI to CO, we realized there is no way our two large dogs could sit comfortably for 14-17 hours in a small car to make that trip. So, we traded in my Civic, which seemed the logical choice based on mileage, age, value, etc. at the time, though I’m questioning that now!

    In general, our dogs ride in our vehicle approximately once every week or two – during the summers they ride much more frequently because they hike with us and get to go to the park. We also will almost always take them with us for any trips, especially when traveling back to WI because I prefer not to pay to board them (not to mention the extra stress on them of being away from us for an extended period of time). HOWEVER, most of the time, I drive my vehicle (a Honda CR-V) alone.

    My husband’s Accord gets about 27 miles to the gallon, on average, and the CR-V averages about 25 (it seems like the Accord should do better than that though…). I have approximately a 25 mile commute each way. There are several factors to us living so far from my job, and so close to his school. It’s not permanent, of course, but for now, that’s what we have to work with. I will of course work to implement some of the changes in this post to help improve my mileage.

    I would LOVE to be able to bike to work, and perhaps some days I will, but as a general commuting option, that is not really the most practical choice. My husband could bike to school, but won’t (I’ve tried, believe me). We just figured we would pay off the CR-V and then keep it until we are forced to replace it. But, is it ever a practical choice to sell the CR-V and trade it in for something that is less expensive but still hits all of our needs, even if we currently have an outstanding loan? The loan amount currently is about $12,800. We purchased the CR-V in February 2012 for about $19,000, in case you want to know the real numbers at all. If you do suggest switching vehicles, any suggestions on doing that (i.e. a good alternative that will meet our needs, and a good selling price for the CR-V – a 2009, basic model)?

    Thanks in advance!

  • cv April 29, 2013, 7:32 pm

    What about idling in the “park” gear? (on automatic)

    • Bakari April 29, 2013, 8:40 pm

      Its a /tiny/ bit better than idling in gear, but it is still far far better to just shut the engine for any stop longer than about half a minute (including even very long stop lights that you just missed)

  • Richard in Canada June 12, 2013, 12:20 am

    Interesting summary collage of thoughts and ideas. Owning a VW gas burning Golf (with that tried and true 2L engine VW have been making for 20 years) now with 4ioooooK on the odo. I still get over 1000km (620mi) highway miles out of a tank of gas (55liters)…and it burns nary a drop of oil…. not even a liter oil change to oil change.

    The secret? Simple

    … don’t drive like a petrol head with pure testosterone for blood… I add 1.5oz of acetone to the gas for every 20 liters of gas..keeps the injectors nice and clean, and seems to improve the octane and fuel economy a bit, and I add 1/2 bottle of Tufoil to the synthetic oil… slicks it up a bit, cuts down on the wear and tear. And I pump up the tires to 37lbs

    Nothing special, no fancy fairings over the rear wheels..

    Saw an original Honda Insight the other day and it reminded me that this was the original and to this day the ultimate hybrid gas miser. Hypermilers gave gotten upwards of 160mpg out of.an Insight….and it was a gas buggy too..Imagine if it had been a diesel.. . .



    . .


    • Mr. Money Mustache June 12, 2013, 3:39 pm

      Wow, that’s pretty great mileage – works out to about 42MPG(US), which is very good for a 2L engine.

  • BD October 9, 2013, 7:32 am

    Something about weight & saving fuel:

    The most basic thing my father taught me, long before I got my own car is this: remove any uneccessary weight from the car before you start. If you go visiting relatives, remove the toolbox and the powerdrill. You have been at a camping trip that weekend and been lazy about unpacking, so the tent is still in the trunk? Do it before your next grocery tour!

    Some of my friends have their car so full of stuff, it’s unbelievable! You could easily remove several pounds of plain dead weight, that just drains fuel. No need for fancy mods or (costly) aerodynamic upgrades, just remove clutter!

  • Holo November 12, 2013, 8:05 am

    Is seems you can’t get the really fuel efficient cars in the US?

    We drive a Škoda Citigo GreenTec. It runs 23.8km/l (~56mpg), the undercarriage is lowered to minimize air resistance. It has an integrated stop-start system, which turns off the engine whenever you’re at a hold, and starts again when you push down the clutch.
    The Citigo was perfect when we were just the two of us, but with a baby and a pram, it’s getting a little crammed, so we consider getting the new Škoda Fabia GreenLine diesel. It has same features as the Citigo and runs an incredible 29.4 km/l (~69mpg).

    • Mr. Money Mustache November 12, 2013, 12:56 pm

      Nice examples, Holo!

      And no, we can’t currently get many cars that efficient in the US – if could see the number of single-occupant full-size pickup trucks (5.9L engine, 5000lb curb weight) that people drive around in urban areas here, you would be amazed at how different the preferences of two different populations of the same species can be!

      The good news is that fuel prices and new rules have drastically improved the model lineup already, just in the last 5 years or so. We have a good selection of hatchbacks again, for the first time in almost 20 years! Plus there are more diesels, hybrids, and Tesla is a US-founded company.

  • Elysia November 19, 2013, 1:43 pm

    Could you please discuss hypermiling and snow? For example, from what I understand, the rubber in snow tires is more pliable (sticky?) in lower temps, which is what makes them so great in the snow. I’ve owned snow tires for 5 years now (in Minnesota, where we get lots and lots of it) and I definitely wouldn’t drive without them anymore – it’s a night and day comparison, how well you can drive and handle the car with them vs. with all-season. I only put them on when the weather gets cold enough and snow is imminent, and take them off when the snow season is mostly over. But in the interest of saving gas – are they detrimental? Would they still provide the same safety and performance if I pumped them up to a much higher psi as you do with your tires?

    • turboseize November 19, 2013, 2:36 pm

      All else equal, winter tires do indeed have a higher rolling resistance. But often, winter tires are narrower than summer tires, which cancels out the stickier compound.
      As to tire pressures: increasing tire pressure too much can wear out the tire prematurely and drastically impair handling and ride quality.
      However, slightly higher tire pressures can save a bit of fuel whith very limited side effects. On many cars, tire pressure recommendations are made for optimum ride quality, not long tire life oder efficiency. I would recommend setting tire pressure to the value recommended for maximum load and maximum speed – this will be considerably higher than the “single person, low sped” pressure. Consult your car’s driver manual or look for stickers (common postions: inside filler cap, on the driver side b-pillar, on the sun shields). Going even higher the ride will become much bumpier (although 0,1 or 0.2 bar extra proably wont’t do much danger).
      In former times it was often recommendend to inflate winter tires to 0.2 bar higher pressures than normal, to compensate for the weaker carcass.

      On dry roads, winter tires perform worse than summer tires. But when there is ice or snow or slush, the summer tire does not stand a chance.
      Stay clear of all-season-tires: I do not say all of them are crap. but surely all of the ones I drove were. On dry roads, they perform like a winter tire, and on snow like a summer tire. Well, not really, but nearly that bad. Worst of both worlds, in my opinion.

      Good tires are worth every penny. Any accident will cost more than you can save with cheap tires…

      So buy good tires. Summer tires in summer, winter tires in winter. Personally, I like Michelin, because they last forever (new Continental will perform noticeably better than Michelin, but that performance will not last). You will throw them away when your Michelin still has 1/2 of it’s service life before him…
      But generally speaking, buying a premium brand like Michelin, Continental, Dunlop or Nokia you won’t make a mistake.
      Stay clear of cheap chinese crap. They’re cheap for a reason. The Koreans however have learned to make halfway decent tires (Hankook, Kumho).

      • Samir November 27, 2017, 5:48 pm

        Really great advice on tires, especially the one about accidents considering the average deductible of $500 is more than a great set of tires.

        Tires is an area I will not skimp–higher performance summer tires I can afford and the higher performance winter tires I can afford. Both have easily paid for themselves many times.

        And when looking at tire reviews, be sure to look at reviews of your exact tire size as tire designs and performance vary by the size, even under the same model name.

  • AJDZee January 3, 2014, 12:46 am

    Tonight I inadvertently came some reassurance I was doing tip #4 right (gliding as much as possible), when on this cold winter night my car wasn’t blowing hot air to heat the cabin after a good 15 minutes of driving. I wasn’t burning enough gas to heat a steady stream of outside air at -30C.

    Not until I hit a long uphill did I feel some warmth!

  • Spencer January 17, 2014, 2:44 pm

    Extremely late post here…just found your website a little while ago and I love reading it!
    I remember hearing about a hypermiling term called “per person mpg” or something along those lines…do you remember how to calculate that? Calculating that number might help me to feel better about the efficiency of my slightly unmustachian family vehicle, a 7.3L diesel ford excursion. It gets 17-18 mpg on average. We had an awesome 26 mpg toyota minivan before that but had to ditch it as we have 7 kids now and need a 9 passenger vehicle for family outings.
    Also, as this car is getting old (>210k miles) we may need to replace it at some point. Any suggestions for a more efficient 9+ passenger vehicle? We don’t do new cars so it would have to be a at least 6 years old…


    • jonathan January 14, 2016, 8:27 pm

      Mercedes sprinter 2.3l turbo diesel 23.5 MPG 10 per 100km average town and towing open road comes as a 12 seat pull the back row out for a 9 seat with a bigger boot (trunk)

  • Charlie February 17, 2014, 1:45 pm

    Awesome article, MMM! I have read into hypermiling before and have been applying some of these methods, but this article definitely brought to my attention some that I hadn’t considered before. Thanks!

  • Dan Caboose April 16, 2014, 6:54 am

    Great post, but your description of “pulse and glide” is wrong:

    “Then they put the car in neutral (or even turn it off) to coast down to a moderately low speed.”

    You don’t coast in neutral, and you definitely don’t coast with the engine turned off. You coast in gear: most cars enforce fuel cutoff as long as the engine is above 1500 rpm. If you coast in neutral, the engine is idling as you coast, so you’re still using up gas. Turning off the engine is dangerous for a number of reasons, such as braking power.

    Other than that, as I said, great post!

    • Mr. Money Mustache April 16, 2014, 8:03 am

      Hey Dan.. I would disagree on that technique, although it is a pretty minor difference:
      – coasting in gear forces your engine to spin at highway-level RPMs (say, 2500-3000). Even with the fuel cut off, this absorbs a huge amount of energy as there is lots of friction and air-pumping loss involved in turning an engine. So your speed drops more quickly.
      – Coasting in neutral involves only the fuel required to turn the engine at idle RPMs (800), which consumes much less energy than turning it at highway speed.

      As described somewhere else in this discussion, coasting in gear definitely saves gas when you need to absorb energy anyway (like going down a long mountain road) – compared to coasting in neutral and using the brakes.

      You’re also right that cycling your engine is a little dangerous. This is typically only done by hardcore people when MPG competition is involved, although I’ll occasionally do it when bored crossing the rolling hills of Midwestern I-80 without another car in sight. :-)

  • A Mugwump April 22, 2014, 11:10 pm

    MMM or other hypermillers,

    Ive had the experience of driving behind large trucks before and had one throw a rock which cracked my windshield. Windshield replacements cost upwards of $100. Was my experience abnormal with the rock being thrown? Ive always associated drafting larger vehicles with a greater chance of cracking a windshield from a rock being thrown. If this is the experience of others as well, is the risk of a cracked window every ___ miles worth the ~20% fuel efficiency gain?

  • vr September 3, 2014, 5:14 am

    Number 4 is not that simple in the end. It all depends on the best torque range of the engine. An engine with the best torque on ~2500rpm is best driven on high throttle and lowish rpm, but for example Toyotas 1.6l engines from the 90’s give their best torque at ~4000rpms which means that if driven on high throttle and low rpm (say lower than 3000rpm) the injectors end up being open way longer than if driven on high throttle and rpm in the range of 3500-4000rpm. Shorter injector open time=smaller consumption.

    Japanese cars tend to be “rev-engines” which are meant to be driven on higher rpms than european and american cars that have more torque and power on lower rpm. When driving a car way way under its recommendations for long periods of time the gearbox and engine wear off more quickly as the oil pump won’t pump oil through the engine fast enough and the movement of oil between the gears in the gearbox is slowed down…

    • jonathan January 14, 2016, 9:17 pm

      It is not just the injector open time it is also the number of times also RPM.
      Double RPM, halve the injector opening time, same fuel use more noise wear higher pumping losses.
      Drive up a hill increasing in in steepness full throttle maximum injector opening as the load increases slowing you down less RPM less injection cycles

    • jonathan January 14, 2016, 10:07 pm

      The engine oil pump has a pressure regulator or is variable displacement to restrict maximum oil pressure power wastage and blowing out seals (more pressure is not always better)
      In a manual gearbox generally the bottom of the gears are immersed in oil
      In high performance applications or were the increased manufacturing cost is Justified (planes,boats power generation,trucks} an oil pump with nozzles to bearings and gears. A pressure regulator or a variable displacement pump for the same reasons, Less power is used to drive the pump than immersing the turning gears squeezing the oil out every revolution heating the oil. It also allows for a separate oil tank and filter and cooler.
      Auto trans normally has full regulated oil pressure at engine idle to allow hydraulic operation of clutches and bands

  • Teresa Benson October 12, 2014, 7:54 pm

    Just a reminder to all you hard-core hypermilers out there: please don’t stare (or glance repeatedly) down at your mileage display while you’re driving in traffic! It’s just one more type of distracted driving that ends up in bumper-crunching.

  • Fred Meissner October 16, 2014, 6:22 am

    Great article, and a nice reminder to remove my roof racks…I like the way they look, but they aren’t doing me any good when they’re not in use. I drive a Jetta TDI wagon 5-speed, and have been running it on B99 biodiesel for the last month or so. When it gets cold, I will have to mix it with dirty dirty petrodiesel. I highly recommend to anyone who is looking to get a more fuel efficient car/decrease their dependence on fuel, to get a diesel and run biodiesel in it if it is available. For those in the USA: http://www.biodiesel.org/using-biodiesel/finding-biodiesel/retail-locations/retail-map

    The place where I get mine uses recycled oil from restaurants; it’s recycling what no one wants, and keeps us from using foreign oil!

    • sea March 13, 2016, 2:06 pm

      If the biodiesel is made from recycled cooking oil, it’s a wonderful alternative to petrodiesel. If, however, the biodiesel is made from fresh new oil, it results in even MORE greenhouse gas emissions than petrodiesel. The growing of the oil crop uses more petroleum per unit of energy than simply burning petrodiesel in your car. So you need to look at the source of the oil.

      Same is true for ethanol, BTW. The growing of the crop for ethanol uses more petroleum than the amount of gas that the ethanol replaces in a car. I think biodiesel is better, because at least you can find a recycled source for it, unlike for ethanol. But if you cannot find recycled biodiesel, it’s better to use petrodiesel than brand new biodiesel.

  • George November 21, 2014, 5:15 pm

    How are you able to get your numbers so accurate while only filling up 1/4 to 1/2 tank at a time? You can’t, right? Don’t you have to fill up/top off at the same gas station, using the same pump, using auto-shut-off, etc.?

    • OhYongHao November 24, 2014, 10:46 am

      Your OBDII port provides a lot of information, including the amount of gasoline currently in the tank. My 2002 BMW 525i has a split tank and it reports back the amount in both sides. Using this information a device plugged into it like the Ultragauge can determine the rate of consumption as you are driving, and report back the average consumption over a given duration.

      If you are running it off of only the pump reported numbers and a full tank then you have introduced a lot of variables, as you have indicated, with different stations, pumps, and auto shut-off, etc.

  • Steve Adcock December 22, 2014, 8:57 am

    Hypermiling has completely changed the way that I drive. I used to drive like, well, the typical driver by “closing the gap” between me and the car in front of me. Now, I coast a heck of a lot more and let other cars whip around me and practically slam on their brakes as they approach the stopped cars in front of them.

    And I laugh at the fact that I did that at one point of my life…until I got wiser.

  • Will January 15, 2015, 2:48 pm

    I did a little research online on this and decided to try out a WiFi OBD II scanner which I just ordered for $12 on Ebay. I think it may come with the smart phone Apps, otherwise those are about $5 on the app store. If you have an iPhone you need the WiFi one…Android users can get the more common bluetooth version.

    Happy Hypermiling!

  • Michelle February 27, 2015, 8:47 pm

    I drive a Subaru Impreza with EPA 36 Highway and 27 City MPG. Overall, I usually get over 35, but this winter has been brutal so have been approaching 30 MPG. I am very easy going with my acceleration and braking, slow going, slow stopping, avoid pushing the brake by anticipating future traffic movement and lights, and avoid stopping completely if able in both light and traffic situations. It sounds like from this article, however, that it is more efficient to accelerate more quickly to your intended top speed and then coast or lightly accelerate from there? I have an automatic transmission. Or should I continue slow accelerating? Thanks!

    • Sky February 18, 2019, 2:37 pm

      It’s ALWAYS more efficient to accelerate lightly. It takes exponentially more energy to move something from stop to go the faster you try to do that. Think of starting a sprint–you’ll get tired much more quickly if you start as fast as possible versus casually starting to move your legs to speed up.

  • Karl hungus March 25, 2015, 10:52 am

    No mention of re usable air filter??? I’m shocked. Not only do you never have to buy a new filter (reusable ones last 1 million miles), you also get slightly better fuel mileage.

  • ryry August 21, 2015, 11:17 am

    So true about the Ultraguauge!!! I was not happy when I had to jump through hoops just to get $10 back. I didn’t do it. I do also have a Scangauge too…and seem to use that more due to the way it’s shaped and how it fits on my dash.

  • Glen May 16, 2016, 9:51 pm

    When I bought my hybrid 11 years ago, I read about “pulse and glide” and I thought it was just a way to get the battery assist to kick in when it otherwise wouldn’t, a negligible savings over the long term. Randomly speeding up and slowing down for no reason sounds like a pretty stupid way to save gas, doesn’t it? But it turns out that you will increase your mileage slightly if you speed up and then TURN OFF YOUR ENGINE COMPLETELY as you coast down. You will also lose your power assist steering and brakes. So this really shouldn’t be done outside of a test track, unless you enjoy endangering your own life, and the lives of your passengers and everyone else on the road to save a few cents per tank.
    So my opinion of “pulse and glide” has evolved from “B.S.” to “Absolutely Batshit Crazy.”

    • Jordan June 17, 2016, 4:45 pm

      I’m not sure what type of hybrid you own, however I would HIGHLY not recommend shutting your vehicle off during the glide phase. This is a path to disaster for hybrids.

      As for P&G method, it is VERY effective regardless if you shut your engine off during the glide phase. For example, normal driving of our previous car, 2002 civic, my girlfriend averaged 35mpg city driving. Doing the P&G method, while leaving the engine on took the average up to 43mpg city driving. Sure during the glide phase, with the engine off, you will receive a greater MPG, however, the GF was never comfortable with this.

      I am a major advocate of hypermiling. I was able to get 48mpg on the civic for city driving, and on long distance trips I was able to surpass the 55 mpg.

      Now regarding your comment regarding the dangers of turning your engine off is SLIGHTLY incorrect.

      You WILL lose your power steering, however, you MUST keep the key in the position right before start(so the next position is when the starter kicks on), this will prevent steering lock from engaging. Steering a vehicle without power steering is not impossible, and in fact is how vehicles used to be. Just get used to how your specific car drives without power steering.

      The second thing is the power brakes. You will also lose power brake function, however, you have about 2 to 3 pumps before the brakes become unusable. That means if your vehicle is off, you do still have the ability to slam on the brakes as the hydraulic system is still pressurized.

      I’m not saying this safe by any means, however, I want you and future readers to understand that “your brakes no longer work when the vehicle engine is off”.

      That being said, we no longer own the Civic, and almost 8 years of ownership while hypermiling the entire time of owning it. Due to the savings we received while hypermiling, primarily using P&G techniques, it has allowed us to sell the vehicle and buy a 2012 Prius II for $13k with cash remaining over. The Prius, following very similar techniques as used in an ICE based car, we are able to exceed 100mpg in city(our highest so far has been 117mpg) and the gf can actually keep up with my MPG averages now.


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