That sounds low! I have the same truck (04.5, 4x4 QC/LB, 325/600, 6 spd, stock tires) and drive about 350 miles week of 70% freeway to 30% street and average 17.5 mpg (hand calculated). That is at 65-70 mph on the freeway. I would replace and inspect all the filters & fluid and take it for a long drive to re-evaluate.

 

04.5 do get slightly less mpg's then previous models due to a third injection event.....

 

That's true, but his mpg's still sound poor, especially with a manual tranny.

 

Driving easy with my 04.5, I can get 20+ MPG hand calculated at 65mph. Regular city driving, about 14mpg. I replaced all fluids with new synthetics (Royal purple rears, Fresh Mopar ATF+4, Premium Blue Extreme) and did the Tone Ring Mod. I run 315/75/R17 Cooper ATS tires on stock rims, with 3.73 gears.

For some undetermined reason, some trucks get better mileage then others. It may be the terrain you drive, the temp, the air quality, the fuel quality, or any number of reason, including the weight of your foot.

Check everything, change the fluids, run some cleaner in the fuel. It may help, or you may just have one of the trucks that just doesn't get good milage....

 

Also, check your air filter and replace if in question. That will kill mileage along with low tire pressure.

 

Thanks for all the input guys. My brother also suggested hooking up a trailer and gving it hell. I just put a gooseneck hitch in this past weekend and I have a 6-horse trailer about 25% full of hay so maybe I'll try that. I put a new fuel filter in and it seemed to help the mileage but it still seems underpowered.

 

I'm glad to see my little brother taking my suggestions well...

 

Even wth all the idoling and winter fuel I still get 14 city and 19 hwy. Thats not driving very conservative either. Anything over 65m/h will really suck your fuel mileage down.

 

04.5 truck with 33's, auto and 3.73's,edge juice, and a 12,000 lb winch hanging off of the front end. i get 15-16 mpg with 50-50 driving on winter fuel and 18-19 mpg on summer fuel,50-50 driving.

 

It's nice to read people telling the truth about thier mileage, I don't know what helps them get better. I have gotten a high of 19mpg on my 06megacab3.73auto... usually around 15.5 in town. I bought a painless performance stricker module which helps with the power if you turn it up to 5-7 on the performance level.... wish I knew how to boost the mileage.

 

Ok i took my truck to the dealer Friday and they flashed the computer. The TSB said the re-flash is supposed to improve fuel economy and reduce white smoke on start-up and improve the accuracy of the overhead MPG reading. After driving about 100 miles at 70mph, the overhead claims 18.7mpg. I hope the reading is correct. Better yet, I hope it's low. Saturday morning I started it up and it blew out white smoke and ran very rough for a few minutes just like it always has. However, I started it up again Sunday morning when the outside temp was much lower than Saturday and it ran perfect with no white smoke upon start-up. This seemed a little strange to me but I'm satisfied so far. I asked the dealer to check injectors and lift pump pressure and also check the turbo. He said injectors were fine, lift pump pressure was 7psi at idle and turbo was fine.