With the 6.0 I have very little expeience, but so far I have gained a little with sythetic... Most people here will call me out on that.. I would have before.. But I drive the same abck and forth to work, and my average is up 1 to 1.5 MPG...
Also with a light foot, the TS Performance box set on half has given me about 2mpg.. But that may have to do with the 35's Im running, and dennis wrote me a special program for the... I would think dennis could write a gas mileage program just the same, and they are at no extra cost...
Those are the two things that have worked for me. I am still on the same exhaust and intake.. so no experience...
