I have a 03 1500 hemi that's getting about 7 mpg in town and 12 on the road.truck is always tip top on Mantimence. I've changed plugs, cold air intake, using a programer, new exaust, perfect tire pressures, no check engine lights, and the truck runs just as good as it did when it got 12 in town and 16 to 17 on the road?? Just looking for some ideas?? I love my truck but it's eating me alive on fuel, I realize it's a full size but I've had bbc trucks that got better gas milage than this... I'm open to any ideas!! Thanks!!

 

Did you use the factory plugs or at;east one recommended by guys on here? What programmer/tune are you running? That's rough man..

 

Not to make it worse but I get 7mpg in my rig hauling 75k pounds all day lol

 

That is rough. I have an 03 hemi too with CAI, Flowmaster, and programmer and im getting 11-12 city and 16-17 highway.

 

The plugs are ngk everything I own has ngk plugs. The programmer is a super chips, it helped to start with but it's been steadily getting worse? I used to pull a race trailer and car and still got Around 11.

 

Clean the TB, clean/replace the PCV valve. Check your odometer against a GPS. It may not be as bad as you think. BTW, how are you checking your mileage?

 

I'm with mike on this one. Also you might want to reset your pcm.

 

The over head is only about .2 mpg off of just doing the fill up basic math for mpg. I drive less than 5 miles a day to work and back and itll burn over and 1/8 of a tank it's costing me almost 50$ a week to drive to work every day, maybe 25 miles total if I don't go anywhere else. I'll try all the ideas above and post back cause this thing is getting rediculous!!

 

V8s HATE short trip hopping! You're probably NEVER getting out of open loop. My bet is the TB, EGR & PCV are a caked up mess which need to be addressed. But take the thing out for a good, hard 20 mile ride once a week or so and it'll do wonders.

 

I agree with Hammer. Even 4-bangers get horrible mileage on 5 mile trips vs 25 mile trips.