Same here. I don't see the mileage people are getting either. My mileage is more in line with yours. I've never seen 20 mpg unless I was costing down hill. :-) I believe it is the high profile more than the weight that affects mileage when towing. I have a 2015 3500 dually with Aisin and 4:10 gears.
Tom
Cummins12V98 wrote:
HAND calc! I AVERAGE 9 in GOOD conditions Westcoast no wind at 60mph. There is NO way I can get 19-20 mpg on the freeway at 60 and I have 4.10's and Aisin trans. If I were to fuel get on the freeway drive 60 for 300 miles no wind no stopping or slowing then stop and fuel then hand calc I would be VERY lucky to get 18mpg. Most likely 17. At 75mph towing no wind I can get 7mph.
I can get as high as 10.5 on flat land no wind but then the mountains will be 8 or so.
I tow a combined load of 33K. I honestly don't care what my mileage is.
I don't get the mileage SOME claim but I fuel the tank to the top at every stop and hand calc so I know most peoples claims are inflated. I take the good bad and ugly.
I did not buy my truck for the mileage, I bought it to do a specific job. That is to haul around dependably our 23K home and it does that task extremely well.