Expert Fuel-Saving Tips: How to Get More Miles Per Dollar

You know the usual reasons to drive the speed limit (it’s safer and you’ll avoid a pricey ticket!), but it can also significantly improve your car’s efficiency.

The more you push the accelerator pedal, the more fuel the engine uses. Accelerating hard makes the engine and transmission run inefficiently, wasting gas. So don't stomp on the gas pedal. Instead, whenever possible, press it slowly and smoothly. The idea is to conserve energy by keeping a steady pace.

Stopping harder than necessary wastes the gas you used getting up to speed. To keep a steady pace when braking, look ahead to anticipate other drivers' moves. For example, when you see traffic slowing down, brake early and gently so that you gradually come to a halt behind the car ahead of you. In CR's tests, hard braking and hard acceleration cut fuel economy by 2 to 3 mpg. Hard braking can also wear out your brakes prematurely.

If you’ve ever had your engine automatically shut off at a stop light, then turn on when you pull away, you’ve experienced the stop/start function. Some systems can feel rough when the engine kicks back on, so it’s tempting to disable it. But leaving it on saves a considerable amount of fuel, especially in city traffic, where you spend a lot of time idling. Cars with stop/start turned on used 7 to 26 percent less fuel in tests run by SAE International. Don’t worry about extra engine wear—engines with stop/start systems are designed to handle it. One fuel-saving feature you can skip is Eco mode, which reduces throttle response and shifts to higher gears sooner. CR’s testers saved more fuel by simply braking and accelerating smoothly and gradually.

The less weight you have to move, the less fuel you'll need to use, so make sure you're not dragging around unnecessary extras. For example, you won't need a winter emergency kit if it's summer.

Roof racks and storage boxes increase aerodynamic drag, making your car work harder and use more fuel. So remove them when you’re done. Consumer Reports got 7 to 13 fewer miles per gallon in vehicles with a roof rack and two mountain bikes than we did in vehicles without a roof rack at all. A rooftop cargo box alone costs 5 to 9 mpg, and even an empty roof rack increased fuel consumption by 2 to 5 mpg over driving with a bare roof. Driving around with an empty rack or roof box could cost you an extra $120 to $220 in fuel per year.

Start looking for a gas station when the gauge hits the half-tank mark. You'll have time to find the best price. Moreover, driving with less than a quarter-tank of fuel isn't great for your car. Debris on the bottom of the tank can be stirred up and pulled into the fuel system, potentially causing costly damage. In the winter, keep the tank at least half full. Cold temperatures cause more condensation to build up inside it.

Tests show it is worth the investment. Trying to save a few cents per gallon at an off-brand gas station doesn’t pay off long term. Major gas chains such as Costco, Exxon, and Shell sell what’s called Top Tier fuel, which has extra detergents that keep an engine’s internals clean and improve a car’s longevity and efficiency. Look for a Top Tier sticker on the gas pump, or check the brand list at CR.org/toptiergas.

Probably not. Many automakers recommend premium gas, which has chemical benefits that help a car achieve its advertised performance under extreme conditions—climbing steep grades, carrying lots of weight, or driving on hot days. But unless your owner’s manual specifically requires premium, the results aren’t usually worth the extra cost over regular gas—88 cents per gallon at the time of this writing, according to AAA. That can add up to about $420 extra a year for a 25-mpg car. We checked: In average driving conditions, Consumer Reports tests showed a negligible performance difference when using regular fuel in a car for which premium was recommended.

Most major gas stations offer a few cents off per gallon if you use their credit card or join their loyalty program, such as Shell’s Fuel Rewards and 7-Eleven’s 7Rewards. The difference between the cash and credit price usually ranges from around 10 to 15 cents per gallon. Another option is to pay with a cash-back credit card. While the credit card price may be higher than the cash price, the reward you receive could make using the credit card a better deal. Paying cash can also get a discount.

Consider rolling resistance. The next time you replace your tires, look for models with low rolling resistance based on our tests. They use less energy (and fuel) to move a car.

Buy for how you really drive. The tires that came with your car aren’t always the best choice for fuel economy. For example, some new SUVs come with grippy, all-terrain tires that prioritize off-road capability, and many sports cars ship with soft, sticky performance tires. Both are great for having fun, but you’ll pay for it at the pump because that extra grip translates into higher rolling resistance. Unless you routinely go off-road or to the race track, when it’s time for replacements, switch to more fuel-efficient all-season tires.

Keep them inflated. Properly inflated tires last longer and improve fuel economy by up to 3 percent, according to the Department of Energy. Use a digital gauge to make sure your tires’ pounds per square inch (psi) matches the recommended number in the car’s owner’s manual or on the doorjamb sticker. Ideally, do this once a month, but it’s most important to check after big temperature swings or if the car has been sitting unused for a while.

• CR’s Fuel Economy Guide
• Cars, Trucks, and SUVs With the Best Fuel Economy
• Best Deals on Fuel-Efficient Cars and SUVs
• 10 Tips to Get the Most out of a Tank of Gas
• Study Shows Top-Tier Gasoline Worth the Extra Price
• Best Car Insurance Companies
• Cheapest Car Insurance Companies
• Who Makes the Most Reliable New Cars?
• Top Pick Tires: The Best Car, SUV, and Truck Tires
• Car Brands Ranked by Maintenance and Repair Costs Over Time