Just got back from a 3,000 mile 12 day trip to Yellowstone and the Black Hills. First long trip with our Chevy Express 3500 and overall I was very pleased with it's performance. We were towing the TT in my sig loaded to about 7,200 lbs. Went over the Powder River Pass in WY and entered Yellowstone from Cody and exited through West Yellowstone.
Had one flat tire on the trailer, but we were back on the road in 20 minutes thanks to Rimrock Tire in Cody, WY for the sum of $15.
Trip towing averaged 9.3 mpg mostly going 65-67 mph. All numbers were from a Scangauge. Best towing tank was 10.7 mpg, and the worse was 8.1 mpg. The 6.0/6-speed combo was impressive, I didn't find a grade I couldn't accelerate up if I needed to. Only got a little warm once with the transmission fluid hitting 220 degrees for a few seconds going up the pass. Most of the time it stayed under 200 degrees. Very stable TV/trailer combo. It was a very relaxing drive, even in a stiff crosswind. I watched other trailers get pushed all over the road in the same wind. I imagined their drivers were a bit white knuckled. Overall, the Express is a much better TV than my 2009 Silverado 5.3 1500 was. A small, but noticeable increase in power, but big increase in stability, cooling and payload handling.
We had a great trip. Stayed a few days in Yellowstone and did the whole loop. Always enjoy visiting there.
2012 Express 3500 6.0, 3.42, 6-speed, E2 hitch, Prodigy P2
2014 Grey Wolf 26DBH