I'm looking at a 2500 quad cab with the 6.7l cummins, but would like to get some real world reports on fuel economy. I think I want the 3.73 rear end. New to the forum and any help on this issue would be greatly appreciated.

 

you can expect 13 - 17 avg depending on your driving habits. once you get 20,000 - 25,000 miles on it you will start seeing an increase

 

Anyworse if it's 4wd?

 

Typical for me is 15/17 city/hwy.

 

i just bought one like 3 to 4 weeks ago and i got like 13 to 14 on the hwy and 15 to 16 city but i just put a intake and exhaust on it and now im getting 18 to 20 in city and 16 to 17 on the hwy

 

Even in my 2002 I do much better in the city as long as you keep a light foot.. With mixed driving around here I can pull a good 21-23 MPG now... The trick is to keep your pyrometer below 600*F and boost below 5 PSI and 20+ MPG's will happen...

 

averageing about 14-15 on hwy. Not quite sure about the city cause i dont drive to much inside the city.

 

24 thats impressive! How do you get less mileage on the highway? 20 in the city? I just topped off I put 231 miles on the trip and added 13.1 gallons of fuel so 231/13.1=17.6 mpg. Funny thing is the overhead says 16.1. I just put on the H&S dpf delete and have had no regens- thank god! I have been mostly highway by the way about 70% hwy.

 

24ssm I think you have your city/highway MPG backwards, unless you are listening to the Lie-O-Meter. I have 6,942 miles on my 6.7, and I get about 17 highway, and 13-15 city depending on how many times my engine goes into regen, driving habits and all that crap. I have MBRP cool duals, and it did nothing for performance. The only way you will see any improvement with an exhaust mod is to get rid of the Cat and DPF all together, only if you ware willing to sacrifice your warranty and like the color amber on your dash. I still have the stock intake, but I took out that huge plug in the stock pipe. I didnt gain any noticable power of fuel efficiency increase, but I can hear the turbo alot more now. I have a 2 1/2 inch lift and 35 inch tires,from which I gained a MPG from, and 200 RPM less at 65 MPH. I lost a couple MPG in the city though. I have the 6 speed manual. I am about to go in for my first official oil change. Gonna get an oil analysis as well. I will let yall know what I find. Oil change is not due for another 3,000 miles or so, seeing that they changed my oil at 3400 miles due to that oil leak I had.

 

123,907 - 123,558 = 349 Miles

349 Miles / 14.893 Gallons = 23.43 MPG

The wind drag on these truck is impressive... But its really surprising to reduce the speed and watch the MPG climb rapidily. Here is a simple write up I did in regards to MPGs...
http://mopar.mopar1973man.com/2002-d...-mpgs/mpgs.htm

Here is my fuel logs...
http://mopar.mopar1973man.com/2002-dodge/2002-dodge.htm