I am thinking about getting some MMW Headers, and wanted to know if there is any reason my mpg will suffer from this instal. Also wanted to say that my first highway experience with my K&N SRI delivered HIGHER mpg than stock. I went 230 miles on half a tank. Half of that was WITH AC. Anyways, would headers(4-2-1) and s-pipe do damage to my mpg???
Thanks,
-K-