This past weekend was the first time I got to use my truck since I purchased it last fall which was stored last winter,I had to travel 175 miles to pick up my enclosed 28' trailer and bring it home I was anxious to see the mileage both ways:
Specs
3.54 gear
32" tire
On the way there I ran 3mph above the posted speed limit which was 58 and 68 mph average RPM 1600 The V 10 used 11.2 gallons in 175 miles which equates to 15.62 mpg. I guess that's the good.
Now the bad and the butt ugly… Hooked up the empty trailer no wind to speak of,O/D off..let's put it this way the gas light came on as I pulled into my driveway… doing the same 3 mph over speed limit average RPM approximately 2400 and 180 miles later 30.02 gallons of gas which equals basically 6 mpg.
Can't wait to put in the 4.10 gears :-)
No matter what it was a great ride love the torque I just won't be doing a lot of long-distance driving I'll pull my trailer with the 36'motorhome at least that gets 8mpg

 

It's because you tow with od off.


At highway speeds on flat ground it's fine to cruise with od on. Otherwise keep it off.

 

Not hauling a load....... O/D generates a lot of heat in the best of conditions. But a load on the back of the truck, and it only gets worse. I think it would be interesting to see what a trans temp gauge had to say...... (as cooking the fluid is what we are trying to avoid here.)

 

a few times I did put it back into OD and the RPM seemed to stay higher most likely cuz of the tall tire and 3.55 gear, a 4.10 gear will definitely help

 

4.10s will make your rpms go up not down.

If you're going on a flat road you're not putting any extra load on it. The brick with wheels and the load WANTS to go the same speed.

I got 200k out of my trans.


everyone should install a larger trans cooler anyway