The 2012 Mazda Mazda6 is available as a 4-door, 5-seat sedan. Starting at $20,480, the 2012 Mazda Mazda6 i Sport (M6) is powered by a 2.5L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 21-mpg in the city and 30-mpg on the highway. The top of the line 2012MazdaMazda6s Grand Touring (A6) , priced at $ 29,810 , is powered by a 3.7L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 27-mpg on the highway.