My truck is an 04 club cab with the 4.7 and four wheel drive. It has never got the mpg I felt like it should but lately it has gotten a lot worse. A Tank of gas isn't lasting like it used to.

I'm getting 10 combined unloaded and 7 loaded. That is with no functioning AC and tires at max inflation. Stock ride height and tire size with Hankook all terrains. Plugs, air filter, coil packs, and map sensor have all been done recently.

It runs like a top and hasn't lost any power. Are there any likely culprits for fuel economy this poor?

 

Maybe the problem is that foot on the gas pedal? How much are you laying into it? How many miles? Are your brakes dragging? Have you ever replaced any of the O2 sensors?

 

I do get on the gas a little when towing because it's hilly where I live but I purposefully drive like a grandpa otherwise to try and help my mpg. My driving habits haven't changed but my gas mileage has dropped noticeably in the last couple thousand miles.

The truck had 132,000 on it when I bought it two years ago and has 165,000 on it now. The dealer I bought it from did not have service records so I'm uncertain if the 02 sensors have ever been done. The brakes were done in late Fall last year.

 

This is a symptom of a lazy O2 sensor. Replace it with a Mopar unit.