The 2007 Pontiac G5 is available as a 2-door, 5-seat coupe. Starting at $14,775, the 2007 Pontiac G5 Base is powered by a 2.2L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 25-mpg in the city and 34-mpg on the highway. The top of the line 2007PontiacG5GT , priced at $ 18,425 , is powered by a 2.4L , 4 - cylinder engine mated to a manual transmission that returns an EPA estimated 25-mpg in the city and 34-mpg on the highway.