Let me make something clear - I have no information on performance gains with these mufflers. My stock ones were getting old, and I enjoy the looks/sound of aftermarket exhaust systems. I bought these for $86 each and got them installed for $100. Some people have gotten custom piping for an additional $100 - which I believe makes the system very comparable to a cat-back system you might buy from a company such as Greddy or Stillen (but I'm not sure). OBX mufflers are stainless steel - so they should last a long time.