...when I sell the K5. The 700r4 and the 2.73 gears makes the truck idle when cruising on the highway. I have been commuting 25 miles each way to work for the past 4 days (200 miles so far) and the truck has barely used a 1/4 tank of diesel (31 gallon tank). I figure that the truck is getting around 25mpg on the highway. I will see how long this tank lasts and report my true findings.