I bet you are running about 7 or so. Thats about the best I have heard on those. If you change the exhaust, the intakes must be changes to make it breathe better. Then you need to go into the pcm and change the horse power ratings, max rpm and in the ned you may, just may, get 1 or 2 miles per gallon increase.
Roy
Wednesday, July 11th, 2012 AT 3:18 AM