its main purpose is to keep the pipes hot and the air from cooling tward the end of the pipe. When the air cools it condenses and is harder to push and u theirfore lose horsepower. (suposidly) anyhow yes its very effective but becarefull if u get it used gloves. if you handle it barehanded ull have nasty splinters that will irritate the crap outta you all night. <img src="/forums/images/graemlins/barf.gif" alt="" />

Welding and Fabrication Engineer
2003 taco V6 ext cab sr5
1988 Toyota Pickup V6(totaled)