Consumer Reports recently put several compact and midsize sedans to the test to find which were the real winners in the fuel efficiency race. The most fuel-efficient, five-passenger, gasoline economy car with an automatic transmission was the Toyota Yaris, which gets 32 mpg and served as their base for comparison.
In testing they found three popular midsize sedans that did almost as well as the Toyota Yaris: the Honda Accord at 30 mpg, Nissan Altima at 31 mpg, and the Mazda 6 at 32 mpg.
A few small sedans faired just as well as the midsized options. The Toyota Corolla and Mazda 3 Skyactiv also get 32 mpg overall. The Ford Focus gets 31, but only with a special Fuel Economy package, a $495 option. Other small cars came out as worse than the midsize options, getting between 26 and 29 mpg.
One of the reasons for the midsize sedans efficiency is aerodynamics. Larger, longer sedans give more room for air to flow smoothly around the car then smaller shorter models, which reduces drag while highway driving.
Midsize sedans are also more expensive and come with more advanced fuel systems that may not be cost-effective to use in smaller vehicles. Consumer Reports says not only are midsize sedans more comfortable and versatile, midsized sedans also safer in accidents, all other things being equal.