HEH, there is no sound difference at all between the two types of material. we offer the aluminized kits, in order to make the exhaust cheaper to afford. the only difference is the life of the pipe. aluminized steel is just like factory car tubing, it usually lasts about 5 years before any signs of wear occur. we do recommend stainless kits for those who live up north. otherwise aluminized kits will last along time, even longer in the south.
josh
YDP Performance
