The biggest benefit so far is better shifts, they feel quicker and more sure now. The gas mileage is up less than 1/2 mpg for city/highway and a little more for highway driving. The Hypertech will take 4 years just to pay for itself at that rate. That said, I am eager to find out if the Hypertech helps when I put oversize tires on. On my old truck bigger tires cost 3 mpg. I hope to at least break even with bigger tires and the Hypertech on the newer truck.