The Porsche 911 GT3 RS (997.2) is an updated version of the previous 911 GT3 RS (997). It has a new 3.8L Flat-6 Engine compared to the previous 3.6L Flat-6 engine, a newly fitted titanium exhaust muffler and tip, and a lithium-ion battery. These improvements allowed the newer model to gain 35 more horsepower and weigh 11 lbs less.