The 2017 Nissan Altima is a 4-door, 5-seat Sedan, available in 7 trims, ranging from the 2.5 SR to the 3.5 SR. Upon introduction, the $24,470 2.5 SR is equipped with a standard 2.5L, 4-cylinder, engine that achieves 26-mpg in the city and 37-mpg on the highway. an Automatic transmission is standard. The $27,990 3.5 SR is equipped with a standard 3.5L, 6-cylinder, engine that achieves 22-mpg in the city and 32-mpg on the highway. an Automatic transmission is standard.