i just bought a 2003 1500 QC 4x4 short bed 4.7l auto and for the past few weeks i've only been able to get around 10mpg. it had the leveling keys in the front and 35inch tires on it when i bought it and i took the 35's off and put 265's back on. i've replaced plugs, airfilter, cleaned throttle body, ran some injector cleaner in the gas tank, when i drive i try to keep it under 2500rpm but no luck. is there anything else i can do to help the mpg out? thanks for the help.

 

Well, it is a 4x4. Is that mileage in town or highway? Just to be clear, how are you determining that mileage?

 

With it leveled and 35" tires originally, the rear gears may also have been swapped. If so and you swapped to smaller tires with lower gears you could make the issue worse. Smaller tires mean more RPMs

 

thats the mileage im getting is in town. im getting the average from filling the tank full and resetting the trip meter. the next fill up dividing the mileage i went from how many gallons it took to fill it which has been around 9-10mpg.

the truck has the stock gears it it. when im running 65mph the truck runs around 18-1900rpm's.

i've always used shell or mobil1 gas so im not using cheap gas. i just dont know why this thing is getting horible gas mileage in town. any other suggestions?

 

that is bad.. im currently getting exactly 11 mpg on e85 keeping it at 2000 rpms or less and im only driving in the city and on dirt roads

 

There have been numerous claims that the 4.7L needs to be up in the rpm range to get better gas mileage because the engine actually works less. I know this is the case in my Hemi. I have it shifting at a much higher rpms than stock and have been getting much better mileage around town.

 

Sounds like you've got the intake side covered, so that leaves clogged up cat's, or muffler, or there's a sensor bad confusing the computer.

You didn't mention total miles on the truck. I'm assuming a 2003 isn't overly worn yet.

I'm not a patient driver at all, and I still get about 13-14 in town.
2008 QC, 4.7 6sp Manual 3.55 gears (waaaah)

 

You have to remember you bought a Full size Truck not a VW. The MPG's goes with the territory. It's about going from point A to point B LOOKING GOOD.