[Rev411]

The mods I have added on previous trucks that will gain about 4 MPG increase through their collective use are: headers, CAI, CAT-Back, under drive pulleys, and electrical fan. No single mod give much noticable gain in mileage but collectively the afforementioned yield 4-5 MPG increase on my 98 F150. I got about 3 MPG improvement on my 96 T100 with an electric fan, light weight crank pulley, CAI, headers and straight through muffler since I could not find a CAT-Back for it. The CAI, headers, and CAT-Back helps with air flow, while the under drive pulley and electrical fan help to reduce the drag from belt driven engine components. As with increase MPG, collectively, these mod work to produce the best HP gains in a non-aspired engine vs. using only one stand alone mod. Hope this helps.