I got a 2009 G8 GXP and I was wondering if I really would get more horse power with a K&N intake or if the stock one is good?

I don't know why they would put such a big intake on the car if it wasn't good but I don't know...

try ls1tech.com go to the ls4 front wheel drive section many ppl have put the ls1,ls2 even the ls6 intake on the pontiac gp gxp,impala ss monte carlo ss etc

yea they got some nice stock intakes there not bad at all but k&n will give more hp and a lil better sound out exhaust but make sure u get one with the box that goes around the filter if you dnt it will get hotter air instead of cold then ur hp will decrease sum. and best thing to do after that ifur not doing an exhaust is to go geta dino tune and unlock all ur true hp wait till exhuast if you r doin one cuz they can tune it way better.