The 2010 Pontiac G6 is a 4-door, 5-seat Sedan, available in 3 trims, ranging from the Sedan to the Convertible. Upon introduction, the $21,275 Sedan is equipped with a standard 2.4L, 4-cylinder, engine that achieves 22-mpg in the city and 30-mpg on the highway. an Automatic transmission is standard. The $32,300 Convertible is equipped with a standard 3.9L, 6-cylinder, engine that achieves 15-mpg in the city and 22-mpg on the highway. an Automatic transmission is standard.