A fuel-efficient vehicle saves money every time you fill up, and it pollutes less. But the label on a new car is only half the story. How you drive and look after a car decides how much of that efficiency you actually get. This guide covers both: what to look for in a fuel-efficient vehicle, and how to get better mileage from the one you already have.
What makes a vehicle fuel efficient
- Weight: every pound has to be accelerated and carried uphill. Lighter cars need less energy.
- Aerodynamics: at highway speed, most of the engine's work goes into pushing air aside. Low, smooth shapes beat tall, boxy ones.
- Powertrain: a small, efficient engine, a hybrid system or an electric motor wastes less energy as heat.
- Tires: low rolling resistance tires and the right tire pressure cut the energy lost where the rubber meets the road.
Types of fuel-efficient vehicles
Hybrids
A hybrid pairs a gas engine with an electric motor and a small battery that recharges itself while braking. You fill up like any car, no plug needed. Hybrids shine in city traffic, where a regular car wastes the most energy. Many of the most efficient hybrids are rated around 50 mpg combined.
Plug-in hybrids
A plug-in hybrid has a bigger battery that you charge at home, good for a typical daily commute on electricity alone. On longer trips the gas engine takes over. They pay off if you plug in every night, and much less if you don't.
Electric vehicles
An EV uses no gasoline at all. Its efficiency is shown in MPGe (miles per gallon equivalent) or in kWh per 100 miles. What it costs to drive depends on your electricity price and whether you can charge at home.
Small gas cars
A compact car with a modern gas engine is still the cheapest way to buy efficiency. It won't match a hybrid in town, but it costs less up front and is often close on the highway.
How to compare fuel economy
Every new car in the US has an EPA fuel economy label. Look at the combined MPG (or MPGe for EVs) and the estimated annual fuel cost. The government site fueleconomy.gov lets you compare any models side by side, including used cars.
One thing the MPG number hides: the savings shrink as the numbers get bigger. Over 10,000 miles:
| Switch | Gallons used | Gallons saved |
|---|---|---|
| 15 → 20 mpg | 667 → 500 | 167 |
| 25 → 30 mpg | 400 → 333 | 67 |
| 40 → 50 mpg | 250 → 200 | 50 |
Replacing a thirsty truck or SUV with a slightly better one saves more fuel than trading a good hybrid for an even better one.
How to make any vehicle more fuel efficient
You don't need a new car to use less fuel. These figures come from the US Department of Energy and EPA at fueleconomy.gov.
Keep your tires at the right pressure
Correct tire pressure improves gas mileage by about 0.6 % on average and up to 3 % in some cases. For every 1 PSI that all four tires are low on average, mileage drops by about 0.2 %. It sounds small, but it is free, takes five minutes and also makes tires last longer and brake better.
Use the pressure on the sticker inside the driver's door, check once a month, and check again when it gets cold, because cold weather lowers tire pressure. Our free air map shows where you can fill up without paying.
Drive smoothly
Fast starts, hard braking and speeding can lower gas mileage by roughly 15–30 % at highway speeds and 10–40 % in stop-and-go traffic. Look ahead, coast toward red lights and use cruise control on the highway. Mileage also falls off quickly at higher speeds, so a few mph slower on the interstate adds up.
Lose the extra weight and the roof box
An extra 100 pounds in the car costs about 1 % in mileage. A large roof cargo box is worse: about 2–8 % in the city, 6–17 % on the highway and 10–25 % at interstate speeds. Take it off when you don't need it.
Keep up with maintenance
Use the motor oil grade your owner's manual recommends, fix warning lights early and keep the wheels aligned. A car that runs as designed uses the fuel it was rated for.
Quick checklist
- Check tire pressure monthly and fill to the door sticker value.
- Accelerate gently, anticipate stops, use cruise control on the highway.
- Empty the trunk and remove roof racks or boxes you aren't using.
- Stay on top of oil changes and alignment.
- When you buy your next car, compare combined MPG and annual fuel cost on fueleconomy.gov.