The G5 comes in two trims: Base and GT. It has a semi-independent rear suspension, rear spoiler, and steel wheels standard. The base model is powered by a 148 hp Ecotec 2.2-liter inline-four engine. The GT is powered by a 173 hp 2.4-liter inline-four engine. Both engine plants are controlled by a five-speed manual or four-speed automatic transmission.The Pontiac G5 is an all new model for 2007.