MPG: 32/40; Base Price $17,835. The stylish compact Hyundai Elantra gets its best mileage in the Eco version with a 1.4-liter turbo-four engine and seven-speed automatic transmission. The rest of the line is rated between 22/30 mpg and 29/38 mpg depending on the trim level and powertrain, which makes other versions as much as $450 costlier to drive 15,000 miles each year. At that rate, however, it would take a motorist nearly six years to recover the $2,600 additional cost over a base SE with an automatic transmission.