We just returned from an 1,110 mile trip towing the monster camper (35' ft. long travel trailer, about 9,500 lbs. loaded). Last years trip the truck was bone-stock, with about 3,000 miles on it. We averaged just under 10 MPG as per the DIC. This years trip was done with the same trailer and driving style/conditions. The truck's Predator was set on the 65 RWHP tune, and I installed the 4" Corsa just before we left. Hand-calculated, we averaged 13.5 this time around. The truck now has just over 15,000 miles on it. I'm sure it's a cumulative effect from the mileage, exhaust, and programmer, but it was a noticeable improvement. We cut out an entire fill-up, and I pulled up the driveway with half a tank. This truck only gets better. Had a Powerstroke parked next to us, and another Duramax on the other side. The PSD was only getting about 11 MPG with a Superchips tuner and the 5" Summit exhaust. The guy in the LB7 was pulling lighter, with no mods, but still getting over 13.

Mark