The 2012 Chevrolet Sonic is available as a 4-door, 5-seat sedan. Starting at $13,865, the 2012 Chevrolet Sonic 1LS Sedan is powered by a 1.8L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 26-mpg in the city and 35-mpg on the highway. The top of the line 2012ChevroletSonic2LZ Hatchback , priced at $ 18,625 , is powered by a 1.8L , 4 - cylinder engine mated to an automatic transmission that returns an EPA estimated 25-mpg in the city and 35-mpg on the highway.