MILEAGE is really poor especially at $2.59 a gal here.

[Trophy1]

I have an stock,03,2500HD,HO,4x4,SRW that no amount of driving like a little old lady will improve the mileage. Is it normal for this truck with 30000 miles on it to still be getting 13 town and 15. 5 highway? Is there a update on the program for this vehicle? I have tried all the normal things to improve my mileage. We are paying $2. 59/9 here at the pump.

 

[Pawpaw]

I haven't seen too many people complaining about fuel mileage on the pre-'04. 5 trucks.



Mine will get about 18. 5 in town and just over 20 on the highway at 70 mph. Are you hand calculating or going by the overhead?



My overhead is not accurate. My last trip, lightly loaded, I hand calculated 20. 3 mpg. The overhead showed 18. 8.



Bob

 

[Rwhedges]

I also havent seen many complaints with the 03's. I just returned from Florida to Indy and hand calculating it showed nearly 2 mpg diff from the overhead. Just the 2 receipts I have right here are overhead (18. 0) hand cal (19. 7) and #2, overhead (18. 2) hand cal (20. 029). During these 2 runs I was doing 70 mph (sometimes maybe a shade over or under) and the roads were somewhat hilly as it was from Jackson, GA to Franklin, KY. I have a stock 03, 2500HD, HO, Auto w/3. 73.

 

[MFalkinham]

I have an stock,03,2500HD,HO,4x4,SRW that no amount of driving like a little old lady will improve the mileage. Is it normal for this truck with 30000 miles on it to still be getting 13 town and 15. 5 highway? Is there a update on the program for this vehicle? I have tried all the normal things to improve my mileage. We are paying $2. 59/9 here at the pump.

I'm curious, does your truck have 3. 73 or 4. 10 gears? Automatic or manual transmission?



Also, have your air and fuel filters been changed recently?

 

[tae73]

I am also getting about the same mileage but at these speeds 75mph=15-16mpg and around town I get 14-15. But if I can run 60-63 mph I can get upwards of 20 mpg. I have 285's with the 3. 73 6spd, if any has any other advice I would more than glad to hear it.

 

[john3976]

You might also try changing your rear end lube to something like the Royal Purple, Valvoline or Mobile 1 GL-5 gear lubes. There are other brands as well.



Might help with friction and help you out a little on the mileage.

 

[Trophy1]

Thanks for the reply guys. I do have a 48RE trans and 3. 73 gears and I changed the rear fluids last fall with synthetic gear lube. As a matter of maintenance I have flushed the 48Re and installed a new filter in it also last fall. I would be ever so happy to be getting your mileages. I always hand calculate my mileage as my over head is about 1 mile per gal off in there favor. I also have replaced my air filter at 20000. I have 265 tires and I rotate my tires every 5000 miles and keep them infated to 70psi.

Is there a service bulletin out on this poor mileage problem Oo. ?

 

[MFalkinham]

My truck doesn't have the HO or 4x4, but with 17k on the clock I have averaged 21. 4 during the last two tankfuls, 80% highway/20% city. My hand calculations match the computer numbers exactly.



Are you using any diesel fuel additives? I've been running a mixture of 12 ounces Power Service Kleen with 4 ounces of Primrose in every tankful.

 

[Gypsyman]

There's plenty of threads about 03/04 trucks getting poor mileage. Mine actually gets better mileage in town and only averages about 15 at 75 mph. I'm hoping that Don's EDMs will bump her up a couple.



Richard

 

[CPG]

In working in major truck shops for 36 years, I never saw much difference in the different brands of gear lube or engine oil. Possibly the additives will show a small difference but I rather think not. We bought it by the bulk in barrels & changed brands often. Just my opinion here.



Chuck

 

[Fred Swanson]

Throw a mild box like the quad, and you should see it go up. My 03 DRW got 12-13 all day long when new. It has gotten better, never worse though.

I don't drive slow, and highways around here are all 75, so I don't drive 55.

Now with 37's, it stays around 15.

 

[WM-300]

I cant give you city MPG as I live very remote. However highway/interstate I am getting in the high 19. x to low 20. x (hand calculated). WHen I hook up to my Gooseneck trailer with a Power Wagon on board, my GCVW is 19,500# and I am getting in the 16. x mpg (hand calculated). I find the magic number is not to exceed 65 mph. My Ram is a 03, HO/6 Speed, 4. 10's bone stock

wm-300

 

[Joseph Donnelly]

In the TDR several years ago, regarding the mpg topic, we were told to subtract about 1 mpg for each: 4x4, dually, automatic trans.

 

[F-15I Ra'am]

How often do you change your fuel filter?I change mine every 10,000 miles. Run some Power Service grey bottle. Most important quit driving like an old lady!Run that truck hard Oo. ,the harder you run these trucks the better they do,there not like gassers.

 

[CPG]

The rule of thumb on changing the fuel filter by Cummins & Dodge is @ every other oil change unless you go with the extended way. Oil is cheap and I do mine every 3-4 thousand miles because of too much local use. Ten thousand is about right.



Chuck

 

[DAT]

Drag increases at the square of the speed increase. In other words, slow down if you want to get any mileage out of your truck.



There might be a problem with the engine calibration if you're getting bad mileage in town and on the highway, but if you're getting similar mileage on the highway as in town or worse on the highway, you need to slow down.



The only reason why you get better mileage on the highway is because you eliminate all of the idling and stop-and-go conditions from town driving. If you're doing 75-80mph a lot of power is required to push your truck through that drag.

 

[RedRam401]

Drove from OKC, OK to Bakersfield, CA a week ago and got an average of 15. 6 running 70 to 75, but after filling up on CA fuel got 21. 0 running down to LA (all overhead). Sure has me wondering if the CA fuel has more BTUs

 

[nickleinonen]

did some calculating, and i got 16. 33 us mpg [calculated from 14. 40 liters/100km] on my last tank, and on this tank, 85% of it was in town, stop/go driving... [and i am not very light on the go pedal]

 

[Elite1]

When I had my stock air box, I noticed the air filter plugging up at about 7500 miles, that was a major reason I went with the AFE system. Don't trust the air minder, some are very sensitive others are not.

It didn't make sense to me that in my 96' a had a much larger stock air box/filter and a much lower HP engine. It seems to me common sense tells us that when you have motor with about 33% more HP you would need more air, not less!

I also change my fuel filter every oil change, they are pretty inexpensive and very easy to do.

I get about 15 to 16 around town and about 19 to 20 on the road, got 22 on one long trip. That is with 3 tool boxes and about 300 lbs. of gravel in a large "golf travel bag" I keep in the far back of the truck to smooth out the ride. BTW: I don't baby it, I like to get where I'm going in a timely manner!

 

[DRicks]

Has anyone looked at changing the thermostat to a hotter 203 and seeing if your mileage increases?