In addition to being one of the most expensive purchases you can make, a car is the one that will most significantly affect a household's carbon footprint. It's not just about the cost of the car itself -- you also have to take into account the cost of fuel and the greenhouse gasses emitted over the vehicle's lifespan.
We've compiled this list of the most efficient cars, with input from our colleagues on the Roadshow team. We've considered the fuel efficiency ratings published by the Environmental Protection Agency and used its efficiency conversion formula to see how electric vehicles stack up against their petrol-fueled alternatives.
It's worth noting at the outset that smaller cars are generally more efficient than larger ones, but we've included the trucks and SUVs that are the most fuel-efficient in their class. And though hybrids and electric vehicles tend to have higher sticker prices, financial incentives available at both the federal and state level can make them considerably more affordable. And that's before the lower fuel costs.
The cars listed here are organized in descending order of overall efficiency, with the top tier populated by electric vehicles. After that, we have plug-in hybrids, which can run on either fuel or electricity. And then pure hybrids, which require both fuel and electricity.
2021 Tesla Model 3 Standard Range Plus
Fuel economy: 150 mpge city, 133 mpge highway, 142 mpge combined
Range: 263 miles battery only
The most efficient EV currently on sale from the biggest name in the game. But the Tesla is more than just slick design and trendiness. It also has one of the longest driving ranges in its class.
Read more: Tesla Model 3 review
Fuel economy: 119 mpge city, 100 mpge highway, 110 mpge combined
Range: 114 miles battery only
The Mini Cooper SE is one of the most affordable electric vehicles on the market. It's priced from $29,900 plus delivery, but when you factor in the full federal tax credit and potential state and local incentives, you could own one for well under $20,000. There's a catch, of course: It has limited range.
Read more: Mini Cooper SE review
Plug-in hybrid vehicles
Fuel economy: 92 mpg city, 79 mpg highway, 86 mpg combined
Range: 126 miles battery only, 200 miles total
To reassure buyers antsy about its driving range, the 2021 BMW i3 offers an optional gasoline-powered engine to provide additional range.
Read more: 2021 BMW i3 with Range Extender summary
Fuel economy: 83 mpg city, 72 mpg highway, 78 mpg combined
Range: 25 miles battery only, 640 miles total
Among the most popular hybrids on the market, the midsize Prius Prime plug-in is also the most efficient in its class.
Read more: 2022 Toyota Prius Prime summary
Fuel economy: 58 mpg city, 60 mpg highway, 59 mpg combined
Range: 702 miles total
The Hyundai Ioniq is available as a hybrid, a plug-in hybrid and a battery-electric vehicle. Each model is remarkably efficient, but the Ioniq Blue hybrid is the most affordable of the bunch.
Read more: 2021 Hyundai Ioniq Blue review
Fuel economy: 51 mpg city, 53 mpg highway, 52 mpg combined
Range: 686 miles total
The 2021 Toyota Camry Hybrid features impressive fuel efficiency as well as a 200-horsepower engine that nets you more than 50 mpg.
Read more: 2021 Toyota Camry Hybrid review
Fuel economy: 23 mpg city, 33 mpg highway, 27 mpg combined
Range: 648 miles total
Though trucks offer far less efficiency overall, the Silverado is one of the most fuel-efficient pickups on the market.
Read more: 2021 Chevrolet Silverado 1500 review
2021 Tesla Model X Long Range Plus
Fuel economy: 109 mpge city, 101 mpge highway, 105 mpge combined
Range: 371 miles battery only
Tesla's pricey electric SUV is built to impress, with a battery that accommodates a longer range than the competition.
Read more: 2021 Tesla Model X review
Fuel economy: 35 mpg city, 35 mpg highway, 35 mpg combined
Range: 598 miles total
Even with all-wheel drive, this three-row family hauler is supremely economical, offering fuel-economy scores that beat what compact cars delivered just a few years ago.
Read more: 2022 Toyota Highlander Hybrid bronze edition