If gas is cheaper at a station slightly out of your way, think twice about riding on empty to get there. Even with the EPA-mandated cleaning additives in fuel, sludge builds up and settles at the bottom of your tank. "If you're running your gas tank on fumes, that sludge is now running through your fuel system," says Barbara Terry, an automotive columnist for the Houston Chronicle and an off-road racer. The pump in your fuel-injection system will start sucking up particles from the sludge at the bottom of the tank if you're running low on fuel. Plus, the pump has to work harder at lower fuel levels—and pump replacements can cost $600. So fill up before the low-fuel light comes on.
Don't: Speed Up or Slow Down Too Often or Abruptly
You've heard about the fuel-saving benefits of driving under the speed limit, but that's just one golden rule. A report this year by the National Renewable Energy Laboratory says fuel-efficient drivers limit the amount of time their car spends idling as well as the frequency and intensity of accelerating and decelerating.
The report suggests drivers slow down by stepping off the gas pedal, instead of braking, to save fuel. And for speeds above 10 mph, accelerate slowly so at least 2 to 3 seconds pass for every 10 mph increase. Essentially, you want to keep the brake and the gas pedal away from the metal.
The overall savings from mastering these driving habits would be 5 to 10 percent for most drivers, and could be as high as 20 percent for some, explains the report's co-author, Jeffrey Gonder. With today's average gas prices, that's 19 to 76 cents per gallon!
Do: Check Your Tires (Really)
We've all heard this one—and we all keeping meaning to check the tires, but a survey by the Rubber Manufacturers Association this year shows that only one in six vehicles has four properly inflated tires, and only 15 percent of drivers know how to check their tire pressure.
Here are a few reasons to head to the garage: Properly inflated tires keep you safer on the road and last longer. They also save you up to 11 cents per gallon, according to the U.S. Department of Energy. The average American buys 558 gallons per year; that means more than $60 in annual savings.
Need a tire pressure primer? The proper pressure for your vehicle is located on the manufacturer's sticker in your doorjamb. Check tires monthly and use a digital gauge to take away the guesswork.
Do: Trade In Your Car
Higher gas prices are likely here for the long haul. And many of us have a gas-guzzler on our hands: The average car on the road today is 11 years old, with a much worse fuel economy than newer-model vehicles.
Trading in your car for a hybrid, diesel or smaller vehicle will save you money at the pump. "The bigger the vehicle, the worse fuel economy it's going to get," Wojdyla says. "It's just physics." If you're turned off by the higher cost of hybrid or diesel options, upgrading to a newer model will save you money at the pump. For example, it takes $200 more annually to fill up a 2000 Honda Civic than the 2012 model. Plus, a decade-old car might be headed toward major, costly repairs.
More Ways to Save Money