So I had enough of my 15 Silverado 5.3, 16mpg. I had a 02 CC duramax that got better mpg. I finally found a 17, 2wd grey Colorado that was just sitting there begging for me to take it home. I like it, its working out. I hope to have many years and 400K before its over. I do want to get as much out of this truck as I can. I hope to find a tune that gets me closer to 40mpg?????? I have to believe that someone on here can do it.