Got the 30 dollar special, and a few parts of pipe. Wow what a diff. It almost sounds like it isn't running at all. The one thing I can say is it may be a little more on the hush side compared to the blown out glasspack, a lil more than expected, but the overall performance of my xj changed none. A+ on thw cheapo special. Close to stock sound (??) but no drop on HP but yet to get MPG......or better yet GPM lol.