The 2012 Mazda Mazda3 is available as a 4-door, 5-seat sedan. Starting at $15,800, the 2012 Mazda Mazda3 i SV (M5) Sedan is powered by a 2.0L, 4-cylinder engine mated to a manual transmission that returns an EPA estimated 25-mpg in the city and 33-mpg on the highway. The top of the line 2012 Mazda Mazda3 Base, priced at $24,200, is powered by a 2.5L, 4-cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 29-mpg on the highway.