2009 Pontiac G8 GT with 20x9 MRR Gf6 and Continental 265x40 on Lowering G8 GT New H & R lowering springs YouTube 2009 Pontiac G8 with 20x9 40 MRR Gf6 and 265 40R20 Continental Extreme Lets see those lowering springs! Pontiac G8 Forum. Sport Spring kits are H&Rs number one selling product. Enhance the look of your 2008 2010 Pontiac G8 with a reduced fender well gap. H&R Sport Springs lower the vehicle center of gravity and reduce body roll for better handling. The progressive spring rate design provides superb ride quality and comfort. A lower wind resistance signature will make the vehicle more streamlined and improve gas mileage. If you are only looking to improve one part of your vehicles suspension, you cannot go wrong with installing Sport Springs. Fun to drive, H&R Sport Springs are the number one upgrade for your vehicle. Lowers vehicle approximately front 1. 4" front & 1. 3" rear.