Just wanted to let you know that my mileage increase is very pleasing. I'm running the Loony with 3.73 gears and 35s. Mine increased from 10-12 mpgs to 15 mpg straight up. I went on a trip 100 miles round trip in the Mtns of VT and used less than a quarter tank opposed to just over a half of a tank. I checked mpg with the dash then with a calculator. Both are right on. I do not "Baby" my truck by any means! That mileage is a mix of in town then 80 miles of mtn roads and a short burst on I 91. I'm very happy, Thank You Viv!