With current gas prices, here's 15 tested tips to get your money's worth.
Cruise control: In this road test by Edmunds, use of cruise control on flat terrain resulted in up to 14% fuel savings. Cruise control in mountainous terrain, however, lowered fuel economy.
Watch your speed: According to the US Department of Energy, gas mileage usually decreases rapidly at speeds above 50 mph. For every 5 mph over 50, you'll see a 7% decrease in fuel efficiency.
Cool it: Aggressive driving habits such as rapid acceleration and braking wastes gas. According to Bosch, lead footers can use up to 25% more fuel. A study by the DOE's Oak Ridge National Laboratory found that aggressive behavior can lower gas mileage by 10-40%.
Stop the idling: In a study by Argonne National Laboratory, passenger cars consume .16-.39 gallons of gas per hour of idling. It's believed that 10 seconds of idling uses more fuel than restarting your engine.
Tire pressure: According to the US Department of Energy, 1.25 billion gallons of gas (apx 1% of total consumption) are wasted each year on underinflated tires. Tires naturally lose around 2psi each month, but most TPMS sensors aren't triggered until a tire is 25% or more underinflated.
Spark plugs: The National Institute for Automotive Service Excellence (ASE) indicates that bad spark plugs can decrease fuel economy by 30%. Always change your plugs at the recommended replacement interval and be aware of engine misfire symptoms.
Alignment: Misaligned tires drag instead of rolling freely and can account for a 10% decrease in fuel efficiency. Balance and rotate according to your vehicle's owners manual, but don't hesitate to take your vehicle in if you notice uneven tire wear or it pulling to one side.
Regular baths: Mythbusters episode 127 tested the theory that dirty cars have improved aerodynamics, much like the effect of dimples on golf balls. While the theory proved to be plausible on a truly dimpled surface, the randomly distributed dust particles of a typical dirty car had just the opposite effect. While we believe this is due to the added weight rather than any added drag, the effect was a 10% reduction in fuel economy.
There's an app for that: Use gas finder apps, such as Gas Buddy, to find the lowest prices near you. Maximize your savings by using cash back apps that reward you for each fill up.
Three clicks: Ensure your gas cap is securely closed to prevent fuel vapors from leaking out.
Don't upgrade (or downgrade): Know the difference between the words "recommended" and "required". Using an octane level lower than what your vehicle "requires" will cause engine damage. If your vehicle has a "recommended" octane level, using it may increase performance. However, using high octane fuel on a vehicle calling for standard will not provide better fuel mileage or increase horsepower.
Driving on empty: Gasoline acts as a coolant in your fuel tank and fuel pump. When the fuel level falls below the fuel pump, it starts taking in air, generating more heat and damaging the fuel pump, resulting in decreased gas mileage.
Hard driving: Abrupt braking and accelerating not only decreases fuel efficiency, it also puts added stress on engine and braking components, leading to premature replacement. The EPA estimates that aggressive driving can reduce fuel economy by 33% on the freeway and 5% in the city.
Extra cargo: The EPA allots for 300 pounds of passengers and cargo when running fuel economy tests. Extra cargo results in decreased handling and fuel economy, as well as added stress to vehicle components.
General maintenance: Vehicle neglect results in poor fuel efficiency now, and larger repair bills down the road. Maintain your vehicle according to the manufacturers recommended schedule, top off fluids as needed, and don't ignore check engine lights.