2017 2500hd 6.0 gas up-grade questions

KD4UPL wrote:

RobWNY wrote:
dave, I tow a 2014 27RK Heartland Trail Runner. Loaded it's about 8500 pounds. As for speeds, I go the speed limit. If it's a 55 zone, that's what I do. If it's a 65 zone like on the Thruway or Interstate, I'll do that but much of the time when in a 65 zone, I'm going 60ish if I have the cruise set and I'm on any kind of uphill grade. Like I said, even when I'm not towing, I get an average of 9.3-9.7 MPG and at my age, I'm not driving it hard. I have a buddy who has a 2013 GMC version and he gets about the same with his truck towing his cattle trailer that's about 8,000 when loaded.

Somethings wrong to get that bad of mileage. My truck at work is a 2015 Chevy 3500 4wd with the 6.0. It has a big tool box bed and ladder racks. It's always carrying enough tools and guys to weigh between 9,000 and 10,000. It averages around 11.5 to 12 MPG and that's with 4.10 gears.

I agree something is not right with the truck. Before blackbear tune I got 7.5-8.5 towing and 13.5-15 empty city. Now I get 8.5 -9.5 towing up through Georgia at 65mph and I'm getting 14.5-15.5 city empty. Hwy I'm getting 17.5 at 70mph. That's a fully loaded 4x4 4 door. My fifth wheel is 10K loaded. I have no issues even pulling more then that. I have went over 12k at times and no problems, just make sure that you use the toggle switch on the stalk and downshift prior the hill. It also allows you to lock out the gears that you don't need. I don't know, I just don't have issues with my truck. Pull with diesel and gas and really happy with the 6.0 and 6 speed combo.