well i agree with black_bullet aka (crazy guy with dreads who danced with pretty much every girl at the UA hangout) personally im running 9:1 compression wisecos and going from stock its totally different i still have yet to feel the true power of my car constantly working on it but my car definately sounds better, and i put the 16g on the car for a lil to break in the motor. when i put it on 15 pounds there was definately a power difference from the stock pistons. I hear its harder to tune on pump gas on the higher compression pistons but i think thats not even relevant considering e85 is coming and I would say just because of e85 run the highest compression lol makes me regret not going higher. Plus even if u just run race gas every now and then higher compression= more power with race gas nigggaaaaaa!!!! oh oh oh think of it this way if ur staying on pump gas smaller turbo= run higher compression bigger turbo run lower compression.... i only say that so you can boost in the turbos efficiency on pump gas. so its just an opinion.