I have a 06 Cummins (stock) 3500 Mega Cab (4.10 gears) and I am averaging 16.5 MPG (2 miles per gallon better than my old 03 SD during break in) at 65 miles an hour, 8500 miles on the truck.
I don't believe the motor is broken in yet. I have not towed anything yet, the 5th wheel season is just starting and no snow to go. What is everyone else getting for fuel Mileage?


How about the 1/2 tons with the 5.7 Hemi (same year, mega cab)? My brother is averaging between 10-12 MPG, only 4500 miles on it.

 

TDogg.....Welcome to DF!

Sounds like you are in the ball park for that mileage w/ a MC and 4.10's. It'll continue to improve a bit more into the 15 - 20K range.

That Hemi may get 10-12 unloaded, but watch what happend when you guys throw that trailer on there. He'll be getting 8 and you'll be getting 12 - 14.

 

Welcome! Just curious, are you getting your mileage from the overhead trip computer? As many have noted, the computer is off by quite abit. Your best bet is to hand calculate the miles/gallons for true mpg.

 

I only got 13.4 mpgs on paper this morning going to the market and back( 225 mile trip) haulin a 27ft gooseneck full of produce runnin 75 and 80mph. That aint bad considering I used to get 6mpg out ofmy chevy with a 454cu[:@].

 

if u guys want to get better mileage then i would suggest a propane injection kit, i normally get about 20 on the interstate (not loaded) but if i turn the propane on im am then getting around 26-27mpg, i was hauling about 12-14 yards of mulch around some back roads when i was working a couple of weeks ago and averged about 16.5mpg, i dont think thats too bad, it also adds a good bit of power

 

Thank you allfor the welcome and all the information! I have been very happy with this Dodge and can't wait to hook up the 5th wheel.

 

I don't trust the trip meter much, but it has been pretty accurate when I compare to my calculations.

 

My 04 3500 dually with stock cummins is averaging around 17mpg. According to the trip computer it sometimes gets over 20mpg at around 60mph but will drop to 14-15mpg at around 80mph. I also find that a headwind/tailwind makes a big difference according to the trip computer of 2-3mpg.
I found that the milage on the trip computer shoots up if I change down through the gears (6spd manual box) when I am approaching junctions. Does the cummins shut off the fuel supply completely in this case, or is the computer just going bonkers?