I got about 20 to 21 at 65 to 70 mph. I have an Edge Comp on my 01. I will get more once I get the truck back from my mechanic. I did some cool things to it.
Fire ringed the block, Elec fans, built trans,tranny cooler,super 40 turbo, full 4" exhaust, cryo treaded pistons and 2nd rings (may have been a waste of Money) ARP studs, oil cooler, K and N. I should be getting lower egts. My next step (next year) hopefully will be the gear venders overdrive unit. My goal is to see 30 mpg with 4.10 gears. I'm sure it has been done. I just don't want to sacrifice power to do it. So may I can make the engine work less.

 

Hey Megruda, welcome to the forum. I bought a 2007 2500 4x4 about a year ago. It has the G56 manual trans and 3.73 gearing. In 14,000 I have averaged exactly 15.3 MPG. When you ask the question about MPG, take the answers with a grain of salt. Some guys calculate their MPG every time, but some use the overhead readout which is usually higher than reality. I track my fuel consumption and odometer readings on an Excel spreadsheet. Here is a link to it. I haven't updated the linked file since April, but you get the idea.

 

I have averaged 13.473 miles per gallon since buying the truck in December. I have about 6900 miles on it as well so this isn't bad considering the 37"x13.5"x20" wheel and tire combo with the 6" lift.

Anyway, sucks that gas prices are so high but what can you do?

 

Notice the Subject: Cummins 6.7 MPG, not 2001 5.9.

 

Joel_MD,

That spread sheet is sweet. I wish I tracked like that from the start. I have about 33K on my truck and get 16.21-16.85 MPG/HWY( hand calculated)when driving on flat roads in Texas. I pretty much drive on the hwy. Last weekIdrove 60mph (babying)for 1 tank just to see what the mpg was, and it turned out to be 17.68mpg (Hand) this was the best I've ever had. I felt kind of stupid driving like a granny but I saved some money on that tank. It just depends how heavy your foot is.

 

 

i have 1955 miles on my truck and with me going to work and home i drive 65 and i get 17.1 now and in town not acting like a fool i get 19 but i also have a 6 speed and i shift at 1500 which is low but im saving money but i was also told by my local dealer that the less rpms the mor mpg u will get it does work and the new intake and exhaust i got has worked on mpg its like 4 more than stock but its better than nothing and the sound on the 4inch dpf back its not loud sitting but it does give u a little rumble going down the road

 

That rumble is coming from the engine, not the tailpipe.

 

I also find that about 1700-1800 rpm is where things start to go downhill with respect to mileage.

If I baby the throttle and keep the RPM's down below that while accelerating and stay about 65-68 on the highway I see much better numbers (15/16 city, 18/19 highway, 14 towing 5K load)

If i start getting in a hurry all those numbers go down as much as 2-3mpg or more.
Towing at 80 is 10-11MPG with no headwind, I have gotten as bad as 8mpg at 80

I have 50K on the truck and have hand cranked the numbers since I bought it, so I note differences from tank to tank.

But don't trust the overhead. It lies like acar salesman

 

Well I got my rig out of the dealer and they did some new TSB that just came out for all the bad apples like mine.(DPF problems). I ran througha couple of tanks and my MPG went up about 1 mpg due to the new flash.(Hand Calc). They drilled a fitting after the turbo so they can spray some solvent and clean the turbo and DPF when my CEL comes. Personally I would much rather have the DPF come off but I really don't think Dodge will do it. I might be taking it off with the "BADP DPF Delete" since they are local. I've heard about 3-4 mpg gain. I'll update you guys if so.