 The GT comes with a  6.0 L (364 cu in) Generation IV V8, featuring a 6-speed 6L80 automatic and Active Fuel Management, capable of reaching in 5.2 seconds, with quarter-mile times as low as 13.4 seconds.The G8 GT averages a fuel economy of 15/24 mpg (city/highway).A 6-speed manual was being considered as an option on the GT model, but Pontiac decided against offering it, stating that it would instead be offered as an option on the G8 GXP.