ya from what i have read the LS-4 V-8 in the GXP is like 0-60 in 6.9 sec an the well my 07 blown GT is 0-60 just a few tenths faster. the GT hp is-260 hp an 280 tq an the LS-4 V-8, a 5.3 liter Displacement on Demand (active fuel management) engine based on the legendary LS1 block Output of this version is 303 hp 323 lb ft. It has a shortened crankshaft, and a host of other modifications to make it fit into a FWD vehicle.from what i have seen the GXP is just 1 mpg lower then the GT but i might be wrong.
