In order to compare fairly, we’ve separated current-model hybrid cars from those with ordinary gasoline engines, providing the top five in each category (plus a few runners-up and a quick look at diesels). The Environmental Protection Agency (EPA) provides separate estimates for city and highway driving, plus a third figure for combined driving.
Among the hybrid-powertrain cars, Toyota’s Prius tops the frugality list by far, with an estimate of 51 mpg in city driving and 48 mpg on the highway, for a combined figure of 50 mpg. Runner-up is the new-for-2011 Lexus CT 200h, estimated at 43-mpg city/40-mpg highway for a total of 42 mpg.
Just behind, tied for third place, are Honda’s two hybrids: the Civic Hybrid sedan and the new CR-Z two-seat coupe. Both earn estimates of 40-mpg city/43-mpg highway for a combined figure of 41 mpg. However, with manual shift the CR-Z drops to 31/37 mpg (34 mpg combined).
Ford’s hybrid sedan duo ranks in fourth place. The Ford Fusion and Lincoln MKZ Hybrids are estimated at 41-mpg city/36-mpg highway, for a 39-mpg combined figure.
Hyundai’s Sonata Hybrid sedan scores the fifth spot for fuel economy, at 35-mpg city and 40-mpg highway, for a combined estimate of 37 mpg.
Coming close are the Lexus HS 250h (35 mpg combined) and the Toyota Camry Hybrid and Nissan Altima Hybrid (33 mpg each). Top-rated hybrid SUVs are the compact Ford Escape Hybrid (32 mpg combined), and the larger Lexus RX 450h (30 mpg).
Among conventional gasoline-engine cars, the thrift leaders are the two-passenger smart fortwo coupe and cabriolet at 33-mpg city//41-mpg highway (36 mpg combined).
Several subcompact cars manage combined fuel economy of 33 mpg, including the Hyundai Elantra with either manual or automatic shift (29/40 mpg), as well as the Ford Fiesta SFE (29/40 mpg) and regular automatic-transmission Fiesta (29/38 mpg). Manual shift drops the Fiesta figures slightly. The manual-shift Eco version of the Chevrolet Cruze also manages a 33-mpg combined estimate (28/42 mpg), but automatic drops the combined figure to 30 mpg. Also estimated 33 mpg (33-mpg city/38-mpg highway) is the 2012 Fiat 500.
Next in line, at 32 mpg combined (29-mpg city/37-mpg highway) is the MINI Cooper from BMW, with a manual gearbox. With automatic, the Mini gets a 28/36-mpg estimate.
Only a handful of thrifty diesel engine cars are available in the U.S., led by the Volkswagen Golf and Jetta TDI, which get a 34-mpg combined estimated (30 mpg city and an impressive 42 mpg on the highway). Audi’s A3 TDI earns the same estimate from the EPA. BMW’s 335d diesel sedan gets a 23/36-mpg estimate (27 mpg combined), slightly ahead of the bigger Mercedes-Benz E350 BlueTec (22/33 mpg, or 26 mpg combined).
How the EPA Estimates Gas Mileage/Fuel Economy
Fuel-economy estimates from the EPA are derived by laboratory simulations of actual driving, following a standardized procedure to mimic a typical driving scenario. Manufacturers actually test their own vehicles on a dynamometer, and report the results to the EPA, which later confirms 10 to 15 percent of them through its own testing.
Though its estimates are far more accurate than in the past, the EPA warns that actual gas mileage “varies significantly based on where you drive, how you drive, and other factors.”
Read our top 10 tips for improving your gas mileage no matter what you drive.