I am an owner of a 2002 Ram QC 4x4 5.9L sport 3.92 rear endwith tow package option for about two months now. I have heard of this truck being thirsty but no one says they're getting this kinda mileage. From a full tank to the fuel light switching on I burn 80 liters and cover about 250 kms. I have chased down people driving on the street when i seen them in a truck the same as mine and even they say thats too much. I have done a number of things to get this problem resolved:
[ul][*]throttle body flush[*]fuel injector flush[*]rad flush[*]new thermostat[*]new O2 sensor[*]new spark plugs[*]new wires[*]new cap and rotor[*]checked the vehicle for brake drag[*]brought the vehicle to three different mechanics!![/ul]
Is anyone else getting this kinda mileage or have they ever and what can i do to improve this? I have checked the MPG thread and no one is getting under 10 mpg (not even srt10's). I would greatly appreciate any feedback. Thank you.

 

hmmm, could try checking injector pulse width...might think it's running lean and trying to add even more fuel which are driving up your fuel trim numbers, could possibly be a vacuum leak, exhaust leak before the O2 sensor....otherwise you could have one of the "bad" engines, i have had 3 different 5.9L and every single one of them got different mileage, however none of em were quite as bad as yours, i had one that got down to 10 but never below that.....trade it in for a hemi or a CTD, you'll be happier anyways

 

Appreciate the feedback hemiyellow. One of the mechanics i took it to has already checked the fuel trim. I have tried mentioning the possible leak before the O2 toone mechanic who assured me that my check engine light would happen if that was the case.

 

check engine wouldnt come on if there was an exhaust leak before an O2 sensor because it would think that it's running a little lean but wouldnt necessarily throw the light on

 

oil change? air filters? oil filters? blah blah blah filters? etc... yeah, get an SRT-10 then if you wanna have better mileage than your 5.9 lol. jk. maybe its time to switch to a newer truck... HEMI, CTD? you know, exactly what yellow said.

 

Any accessories that could cause it? Air-deflectors, lift kits, bigger tires, etc. Any chance the previous owner did any internal mods? And lastly, how are your driving habits? Mine suck and I know it.

 

What size rims/tires are you running? And are they inflated properly? Hows your air filter?Do you have the routine maintenance done every 3months/3,000miles? Is it lifted?All these things play a big part in yourgas mileage. If your truck is lifted and on big tires then it will cutyour mileage down quite a bit more than average and if the tires are low then that will shave another mpg or moreoff as well.

 

All stock with stock 20's and bug deflector and fiberglass toneau cover. As far as my driving habits theyre not bad first tank i drove it under 2000rpm and it didnt help any. And the routine maintenance that shoulkd have been done 3 months fro picking it up i've done in the first two weeks of having it to get it out of the way and eliminate it as a factor.

 

I would look into clogged cats. I had the same problem (on a Honda). Mileage went from mid 20's to low teens no matter what I did. My mechanic found my cats broke down and collapsed basically restricting the engine. I had them removed and my mileage went back to normal.

 

do you have any power under acceleration? or does it bog down?