Love my new Colorado Z71 4x4 Duramax Diesel. Longest trip so far to Steamboat Springs, CO, 2,000 miles R/T. 24.5 mpg going driving mostly 80-85, stepped down to 75 on the way back and got 27.5, overall 25.9. With the other 2,000 miles, some freeway, bust mostly around town, 22.6 overall for 4,000+ miles. Looking to buy a 19 to 25 foot travel trailer, around 4,500 pounds unloaded 6,000+ loaded, thinking that will be ideal and not bother the 7,700 pound towing limit. Read quite a bit on the towing forum and found a lot of good information here. Glad I found you all!