Just got a new WT 2500 primarily for towing my toy hauler. Towed it this past weekend from Chesapeake, VA to Charleston SC. Now my camper is only 20' and less than 6000 pounds and towing down 95 which is relatively flat and straight I got about 6.5 MPG. I knew my mileage wouldn't be great but I was expecting atleast 10. The truck is a 4x4 with about 1800 miles on it now. Anything I need to look at? Will the mileage get better with more miles? Maybe it is just because of the wind drag on the camper? Thanks all in advance. I have gotten some good advice from other forums so hoping this one I do as well.


Troy

 

That is pretty lame mpg, even from a 2500 6.0L. And a pickup pulling just about anything other than a platform trailer is an aerodynamic nightmare. But I have read of many others getting 10+ pulling their stuff around. Driving style plays in this as much as anything else does. 6.5 mpg, that is criminal. I get better than that with my semi truck loaded with 45,000 lb of cargo.

 

That is what I was thinking. I hauled in tow mode not using my cruise. Next time I will use cruise and see if that helps. at 70mph I was at about 2700 rpm if I remember correctly.

 

Seems like you are not getting proper torque converter lock up. At 65 I am only turning about 1900. Yes with 6.0L, 6L90 trans, and 4.10 diffs and 18" stock tires. At 70, you should be seeing between 2000 and 2100 RPM. Lack of lockup could easily explain your fuel use. Have it checked out. Tow mode only changes shift points. The engine RPM is relative to the transmission gear ratios and the rear ratio irregardless of in tow mode or not.

 

imo 800 rpm is a large drop to be only a tcc lock up problem. what are the rpms at in manual mode when in and out of tow mode?

what year truck? maybe new models inhibit 6th in tow mode.




As a comparison my 2006 2500HD with 6.0L 4L80E trans, 4.11 pulling a 5000lbs 12 foot uhaul trailer would get 10mpg at worst climbing mountains, 13-15 flat...imperial gallon. I was driving slower 60-65mph.

 

It is a 2016 2500HD. Have to check and see exactly what the tow mode does. I thought that it was shift points also but it might lock out 6th gear. Haven't had a chance to check 70mph out of tow mode. Don't drive the truck often but will check it out soon. Thanks all for the inputs.

 

Ok took it out without the camper and in tow mode or not tow mode I was just over 2000 rpm at 70 mph. Put it in manual mode and it looks like the truck was in 5th gear while I was towing. So now not sure if it was because of the weight or drag of the camper that was keeping it from going to 6th gear or something else. Maybe 70 is right on the edge while towing of being in 5th or 6th gear?