I have a 2004 Dodge Ram Quad Cab 2500 H.O. 4x4 w/ auto trans and I think my MPG's are much lower than they should be.  I just made a trip from Los Angeles to Kingman, Az. pulling my 10,000 lbs 5th wheel and averaged 8.3 MPG and that was keeping the RPM's below 2000.  Around town I average 14. It is completely stock and I have replaced the lift pump (not by choice), fuel filter and air filter and that didnt seem to help.

So my question is, what do I need to do to get the MPG's back up in a respectable diesel range?  

i would start with a cold air intake and some exaust.. then a small chip like an edge eazy that gives you 65 horse.. and it wouldnt hurt to get some gauges so you know whats going on under the hood..  

thats about what they should get. everybody is on this supertruck kick with huge mpg but i have never seen it.  

Before you spending $$$ on peformance parts; go to your dealer or better yet a good diesel mechanic with a computer. I have seen where something threw a code and peformance levels dropped. He may be able to reflash the computer or diagnose your problem.  

spotted ape:
Before you spending $$$ on peformance parts; go to your dealer or better yet a good diesel mechanic with a computer. I have seen where something threw a code and peformance levels dropped. He may be able to reflash the computer or diagnose your problem.

How could the motor "throw a code" without the check engine light coming on? In which case Im sure he would have had it diagnosed.  

consider yourself lucky. mine is a 6 speed single wheel quad cab long bed, and i get 14mpg highway! 11 in town tops! i hate that about the truck! and ive got the chip, and the intake, the intake brought it up about a mile and a half...if anyone has any ideas about mine, please let me know...  

I would have your computer flashed just to see. I got a 06 2500 with a 6 speed and I get 16 in town and 20+ if I drive 65 and under highway. The auto I test drove said 18 when I took on the highway. I have heard of people getting bad mileage with the new motors in any brand.  

Somthing is deffinately wrong.  Unless you're not giving us all the info.  I have an 05 3500 4x4 Dually H.O. w/ Auto 4.10 gears and the stock 235/80 tires and I get 15 mpg in the city (17 hwy).  Tucson is at 2300ft so it would be even better closer to sea level.  You should be getting closer to 17-18 unless you have big meaty tires and towing.  

I have an 06 Quad Cab, longbed, 4X4 auto. 14mpg in the city is about what I get. I have the off road tires also. Personally, I do not think your mileage is so unreasonable.  

the current obd-II systems classify codes in C (chassis) B (body) and P (powertrain)
the p codes have more than one catigory, one being pending codes, some codes require the same fault to occur on multiple consecutive trips before the MIL is set, untill that point it will be recorded as a pending code,still no check engine light, if the fault does not return the code will be stored as a history code. the EPA only states that the MIL be turned on if the fault that's happening causes the vehicle to fail emissions. so it is very possable you have helpful codes in the system. as far as fuel economy goes, ever since the switch to low sulfer fuel we have had more than a handfull of trucks suffer side effects, BG and delphi make cetane/lubricant additives that have helped.  

Have you experimented with different fuel brands? My truck will vary almost 5 mpg from the fuel brand it loves and the one it hates. Not all fuels are blended the same with some refiners using different additives than others. Just my $.02  

There is definetly something wrong.  I pull a 14,000lbs. bumper hitch trailer in a city setting all day and drive home at 75-80mph on a freeway for 300 plus miles a day and I still average 12-13mpg.  I have heard of bad from factory injectors in 2004 but I didn't have the problems but have seen friends that did.  Empty on a hwy with my chip at 56-58mph I have gotten 21mpg.  

JERRY IS RIGHT I PULLED A TINY 6000LB. 5TH WHEEL FROM IL. TO SD. AND WHILE I DIDNT HAND FIGURE THE TRUCK COMPUTER SAID 18.4MPG  

I've got an '03 quad 4x4 2500 Cummins auto and average 16 mpg hwy/city, usually 12 mpg pulling a 24' gooseneck with skid-steer and attachments (3.73 gears and stock tires). I'm interested in the Granetelli Motorsports Mileage Miser, guaranteed to add 3 mpg or full refund (also adds @ 50 hp, 150 ft/lb). Sounds perfect to me, especially @ $300, but I'm curious if anyone has tried it or knows any drawbacks? Would like to modify the truck more eventually, but need to keep it more like stock now as a primary work truck / family truck, except going to a 285/70r17 allterrain tire to better deal with muddy jobsites.  Any advice would be greatly appreciated. She's all stock except for K&N airfilter (45,000 miles & still under warranty).  Thanks!  

Ok first post  NEED HELP FAST MPG SUCKS  I bought a 2005 dodge 4:10 gears DW auto trans 4 X 4 at woodhouse ford/ dodge in Blair Ne   I have drove it 21000 miles since Jan 5th Yes 21000 miles in about 30 days   I am running strait pipe no muffler or res.   I put predator programmer in mpg mode setting 2 Wow it runs great but with or without programmer mpg is 8.2 to 9.2 average my low is 5.2 to 5.9 and my best 13 and that was one tank and this is correct mpg checked by odometer I am towing about 6500 # enclosed but get about 1/2 gal mpg better with the flat bed. Truck has 100003 on chassis but engine pump and turbo was replaced at 71000 75000 78000 miles they have put 3000.00 worth of new parts in 20000 miles on it new valve body new alt exhaust melted old one new exhaust manifold turned front rotors new front axle joints new rear joint ect. We have talked about them buying it back will know Monday if that is going to happen. I have talked with about 50 dodge owners yes 50 and two other dealers they all say something’s wrong with the mpg I pulled a camper for a guy 2100 mile who has pulled it with his dodge 5 time that far and he said the worst he has gotten is 11.5 on a very windy tank that he gets about 15 to 16 with it and 18 to 20 empty but he has a 3/4 ton it has used 12 quarts of oil if not more I think the oil went up a quart I checked it it was down and now its full. I think fuels going in oil and burning it or it’s going out the tail pipe. I have herd they have had an injector problems or some return problems please help Brett 515-321-2777