Shawfamily6 wrote:
Thanks for all of your responses! My husband has informed me that we have a 2500 HD, not a ½ ton ??. We have a vortex 6.0L V8 gas engine, 6 speed with a 410 rear axle. We have 20 inch wheels with a GVW of 9500lbs. It doesn’t have OD, but has a tow haul button. Do most people use this when pulling their TT on the highway? I know my husband uses it when pulling his enclosed trailer in town. We have been driving about 63-65 MPH, so maybe we need to keep it around 60. I really appreciate all of your help! We plan on traveling quite a bit this summer, and with 4 kids we want to save where we can. So if we need to drive 60, that’s what we will do!
Hi Shawfamily6. I do know a lot about GM trucks, I used to work for their Technical Assistance Center. That 2500, with the 6.0 V8 has a lot of pull, but is not known for good gas mileage. The 4:10 axle gives you even more pull, but less mileage. Still, 6 mpg is pretty low. Yes, your 6 speed transmission does have OD, I think both 5th and 6th gears are overdrive gears. Probably you don't get into 6th while towing with tow/haul on. What I would suggest, is to keep speed a little lower, and try putting the transmission into manual and put it in probably 5th gear, and see how that does. Tow/haul is nice, and I use it most of the time on my truck, but it seems more concerned with giving you maximum tow power, and less concerned with mileage. Speed is the enemy of fuel mileage. I can tow at 70, but the mileage is lousy. Way better at 60-63 mph. That said, it is shocking how poor the fuel mileage is when towing a travel trailer.
