The 2012 Nissan Altima is available as a 4-door, 5-seat sedan. Starting at $20,550, the 2012 Nissan Altima 2.5 Sedan is powered by a 2.5L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 23-mpg in the city and 32-mpg on the highway. The top of the line 2012NissanAltima3.5 SR (CVT) Coupe , priced at $ 28,970 , is powered by a 3.5L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 27-mpg on the highway.