Reviewed By Clint B (POCATELLO, ID) Reviewed for a 2004 GMC Yukon —9/18/2014 11:59 PM
All the tunes have a noticeable gain in power and throttle response. I use the same programmer for my 2004 Yukon and 2001 Silverado. Both are on the "mileage xs" tune. I get about 17 mpg city and 20.5 highway in both vehicles. I should mention that I also have exhaust, CAI, and shorty headers on both vehicles. All of those things helped increase mpg. The programmer was the last thing I added and it did give me an increase in mpg from what I was already getting.