The 2015 Cadillac ATS is a 4-door, 5-seat Sedan, available in 30 trims, ranging from the 2.5L RWD Sedan to the 3.6L Premium AWD Coupe. Upon introduction, the $33,215 2.5L RWD Sedan is equipped with a standard 2.5L, 4-cylinder, engine that achieves 21-mpg in the city and 33-mpg on the highway. An Automatic transmission is standard. The $51,435 3.6L Premium AWD Coupe is equipped with a standard 3.6L, 6-cylinder, engine that achieves 18-mpg in the city and 26-mpg on the highway. An Automatic transmission is standard.