How to Lower Your Fuel Costs: Driving and Maintenance Tips

The biggest levers on fuel use are how you drive, how much weight and wind resistance you carry, and basic maintenance. According to fueleconomy.gov, aggressive driving alone can lower gas mileage by roughly 15% to 30% at highway speeds and 10% to 40% in stop-and-go traffic. This guide collects the tips fueleconomy.gov publishes, with its numbers, and turns the percentages into gallons so you can judge what each is worth at your own fuel price.

Key takeaways

• Smooth driving, moderate highway speeds and avoiding idling cost nothing and apply to every powertrain.
• Extra weight and roof cargo each cut fuel economy; remove what you do not need.
• Tire pressure, the manufacturer’s recommended oil grade and attention to the check engine light are the maintenance items fueleconomy.gov highlights.
• Do not pay for premium gasoline unless the manufacturer requires it.
• A percentage saving is worth more on a thirsty vehicle than on an efficient one.

Drive smoothly

fueleconomy.gov says aggressive driving (speeding, rapid acceleration and braking) wastes gas, with the range quoted above. Gentle acceleration and anticipating traffic so you brake less are the habits that follow. Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas, according to fueleconomy.gov.

Watch your speed

fueleconomy.gov notes that gas mileage usually decreases rapidly at speeds above 50 mph. Aerodynamic drag grows quickly with speed, so a few miles per hour less on a long highway trip can matter more than almost any other habit. The EPA’s own highway test tops out at 60 mph; see city vs highway MPG and the combined rating.

Avoid idling

Idling can use a quarter to a half gallon of fuel per hour, depending on engine size, according to fueleconomy.gov. If you will be stopped for a long time, turning the engine off saves fuel. Some vehicles do this automatically; see start-stop and turbocharged engines.

Carry less

• Weight. An extra 100 pounds in your vehicle could reduce your MPG by about 1%.
• Roof cargo. Hauling cargo on your roof increases aerodynamic drag and lowers fuel economy. A roof-mounted box can reduce fuel economy by around 2% to 8% in city driving, 6% to 17% on the highway and 10% to 25% at Interstate speeds of 65 to 75 mph. Rear-mounted containers reduce it much less, by 1% to 2% in cities and 1% to 5% on highways.

Take off roof boxes and racks when you are not using them, and clear out heavy items you do not need.

Maintenance that matters

Item	What fueleconomy.gov says
Tire pressure	Keeping tires inflated to the proper pressure can improve gas mileage by 0.6% on average, up to 3% in some cases. Under-inflated tires can lower it by about 0.2% for every 1 psi drop.
Motor oil	Using the manufacturer’s recommended grade can improve mileage by 1% to 2%.
Air filter	On modern fuel-injected, computer-controlled gasoline engines, replacing a clogged air filter does not improve fuel economy, but it can improve acceleration.
Check engine light	It indicates that something is wrong with your engine; address it promptly.

Proper pressure is the figure the vehicle manufacturer specifies, so check your owner’s manual.

Use the right fuel grade

fueleconomy.gov’s guidance is to use the octane rating required by the manufacturer. Where premium is only recommended, the cost increase is typically higher than the fuel savings. The details are in regular vs premium gas.

Cold weather and electric vehicles

Cold lowers fuel economy for every powertrain; see real-world MPG vs the EPA label for the numbers. For battery-electric vehicles, the Department of Energy’s Vehicle Technologies Office reports that cabin preconditioning while the vehicle is plugged in can save up to 20% of battery energy on short, city-like trips at 20 degrees F, because the energy comes from the grid rather than the battery. It also notes that heated seats consume approximately 50 W per seat, whereas convection-based cabin heating typically requires 2,000 to 4,000 W, and that BEVs with heat pumps are 3 to 4 times more efficient than those with resistance heating. Short trips in the cold are the least efficient for gasoline vehicles too, because of warm-up time.

What the percentages are worth

Percentages become more concrete as gallons. At 15,000 miles a year, a 30 MPG vehicle uses 500 gallons, and a 1% improvement is 5 gallons. A 25 MPG vehicle uses 600 gallons, and 1% is 6 gallons. A 10% improvement on 500 gallons is 50 gallons. Multiply by your price per gallon for dollars: the price moves with the month and place, as explained in how annual fuel cost is calculated. The combined effect of several small items is not simply their sum, and the figures above are averages from fueleconomy.gov, not guarantees.

Which habits to start with

If you want an order, start with the habits that cost nothing: smoother acceleration, steadier highway speeds and less idling. Then take off unused roof cargo and clear out extra weight. Then check tire pressure monthly and use the oil grade in the manual. These are plain steps, and they apply whichever vehicle you drive. To see what your own mileage and fuel price imply, use the fuel cost calculator, and see the methodology for how our estimates are built.