5 Myths About Gas Mileage You Shouldn’t Believe

With gas prices on the rise, it's normal to want to save money at the pump, but don't be fooled by these five common fuel-saving myths about gas mileage.
5 Myths About Gas Mileage You Shouldn't Believe

With gas prices slowly creeping back up, fiscally-conscious drivers will do almost anything to save a couple of bucks at the pump. But it may not be helping. Here are five gas-saving myths that turned out to be not so helpful:

1. Topping off your tank: When you’re at the pump, you want to get as much gas in your tank as you can, right? Wrong. Continuing to pump gas into your car’s tank even after the pump has shut off, indicating the tank is full, is a major no-no. In addition to spilling out on to the ground or all over your shoes, topping off the tank can also hurt your car’s evaporative emissions system, which can reduce gas mileage.

2. Manual transmissions always get better fuel economy: This used to be the case, but advances in transmission technology have improved fuel efficiency on automatic transmissions to the point of beating out most manual transmissions.

3. You need to let your engine warm up: Again, this is a myth that may have once been true, but modern cars are ready to be driven within seconds of starting the engine, but you shouldn’t subject your engine to extreme loads until it reaches normal operating temperature. In fact, the best way to warm up a car is to drive it.

4. It’s important to use aftermarket additives: There’s a lot of hype around “fuel-saving” aftermarket additives, but independent tests show that such devices do little to improve fuel efficiency and may actually harm your engine and/or increase tailpipe emissions.

5. Air-conditioning uses too much fuel: Sure, your engine has to work hard when the air-conditioning system is running, but on a hot day, running the A/C is far more economical than driving with your windows down, especially at higher speeds, studies have shown. Most cars are aerodynamically designed for increased fuel efficiency and rolling down the windows can cause major drag, reducing your overall fuel economy.

But there are still several ways to save on fuel. If your car is going to sit idling for more than three minutes, consider shutting off the engine as an idling car can use up to half a gallon of gas per hour. Also, make sure your tires are properly inflated at all times, as poorly inflated tires are often the biggest culprit when it comes to poor gas mileage.