How to Increase Your Gas Mileage by 70 Percent

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On the most recent episode of Discovery Channel’s “MythBusters,” Kari Byron, Tory Belleci and Grant Imahara tested whether a few techniques collectively known as “hypermiling” can double your fuel economy. They took two cars, a new sedan and an older coupe, and drove normally as far as they could on exactly 3 gallons of gas. They then repeated the process using hypermiling techniques.

The results? The new car was able to drive 40 percent farther while hypermiling (30 miles per gallon, up from 21.3 mpg), while the older car went 70 percent farther (45.3 mpg, up from 26 mpg). The myth is busted, because they couldn’t double their fuel economy, but a 70 percent improvement is impressive. And it could save a lot of money at the pump.

Only driving techniques and modifications legal in California were employed, so everything they did to get that massive improvement in miles per gallon is probably legal for you, too. But since laws vary from state to state, you’ll want to make sure anything you pull from this list is permitted where you live.

Here’s what to do:

Never drive above 45 mph

Yes, this includes highways. And yes, you’ll make a lot of enemies. But if you can pull off driving no faster than 45 mph, you’ll use a lot less fuel.

Remove passenger side mirror

The thinking here is that by reducing wind resistance, you’ll improve mileage. Removing things sticking out from the side of your car should do that.

Avoid braking and rapid acceleration

This is the foundation of hypermiling. Not only do you need to gradually bring your car up to speed, but also drive to minimize braking. This means driving slower overall, looking as far ahead as possible, and braking less around turns.

Turn off engine at red lights

If the engine is off, you’re not using gas. If you can ignore a little horn honking and spiteful hand gestures you’ll get from the cars behind you while you start back up when the light turns green, you’ll spend less on gas.

Windows up/AC off

If you can stand the heat, you can save some money. By keeping your windows up and the AC off, you reduce the strain on your engine and maintain the aerodynamics of your car.

Try to stay relaxed

Angry drivers burn more fuel. It’s a myth that “MythBusters” has already tested, but the lesson learned has become part of hypermiling. If you feel yourself getting stressed behind the wheel (and if you’re driving without AC no faster than 45 mph on the freeway and turning your engine off at every red light, you probably will) try taking a few deep breaths to calm down and remember that your goal is zen-like fuel savings.

Legally draft when possible

This is another technique that’s been tested by “MythBusters” (albeit to an extreme). If you can find an opportunity to legally draft the vehicle in front of you, take it. Drafting is simply driving at a close but still reasonable distance behind the vehicle in front of you.

But while driving extremely close to something like a big rig will save you a ton of gas, it’s incredibly dangerous. Always remember: Your life is more important than your money.

Overinflate tires by 10 percent

Though it may reduce the lifespan of your tires, slightly overinflating them may help you get a few more miles out of each tank of gas.

Cover car in streamlining skin

While it may seem a bit goofy, “MythBusters” covered the cars in some kind of streamlining skin. It’s unclear exactly what they used in this episode, but they’ve already shown that adding dimples to your car can increase its mileage, so a skin might not be so far-fetched.

Try to navigate intersections to always go through green lights

If you have to stop, you’ll have to start back up again. And accelerating up to speed takes fuel. Minimize the number of red lights you encounter and you’ll use less.

Reduce weight

The spare tire in your trunk is convenient when needed, but adds a bunch of weight to the car. If you’re comfortable driving without it, remove it. And while you’re at it, remove anything else that’s adding unnecessary weight, like that set of golf clubs still in your trunk.

Is all this practical?

You’re probably not going to remove your side mirror and spare tire, cover your car with a streamlining skin, or sit in a steaming car all summer. But because you won’t use all of these techniques doesn’t mean you shouldn’t use any.

As we reported in “The 4 Best Ways to Improve Gas Mileage,” simply driving proactively can increase mileage by 37 percent, while turning off your car at lights can save 19 percent. That’s a huge improvement, and one that doesn’t require spending money on silly gas saving devices.

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  • Nukemifugotem

    Except for stopping the engine and removing side mirror, I’ve been using these techniques for years. It’s called common sense. On my older car with a carburetor I accidentally made a slice in my pump plunger when rebuilding it. My gas usage went from $5 a day to $5 for 6 days! But had no “get up and go” power. So I took the carburetor apart and found / fixed the problem. But my gas usage went back to normal along with the engine power.

  • rich

    1. Turning off your engine uses more gas unless you can stop for longer than a minute. Newer cars have low emissions/gas saving idle. Just like it said with coasting, stopping and starting needs more energy than letting it coast.

    2. Factor in that your engine losses heat while off, so when you start up it wont be at the efficient temperature, causing your oxygen sensor to turn off leaving your cars computer to guesstimate proper air to fuel ratio. Under fueling your car can cause preignition which means damage to your pistons, so your car is programed to put more fuel than that is needed so it doesn’t damage your engine.

    3. Starting your car in uses an electronic chock, which uses significantly more gas.

    4. It is illegal and stupid to turn off your car while operating on a roadway, going down a hill or waiting on a red Light. When you turn off your car you lose power braking, antilock brakes, power steering, your steering wheel locks, air bags don’t work, traction control/anti skid. So f you turn off your car at a red Light and get rear ended, you will be pushed right out into cross traffic where your side airbags won’t deploy after being tboned.

    There has been real scientific studies on improving gas milage and they all say don’t turn off your engine. Don’t take the word of a busta, remember those guys are entertainers not engineers or scientist, they might have a degree and field experience but the TV show lacks true scientific practices.