i'd be willing to bet it's not engine related. take a look at your brakes and see if they are dragging. it's cost me a couple mpg on other vehicles, and the rams have a problem with front brakes.

try driving it in tow/haul for a tank. it switches over to a different shift schedule and may help confirm programming as the issue.

just for kicks, stop using that V power. i have heard of rare and unconfirmed instances where it hurts MPG to use higher octane. you don't need it anyway, just pump 89.

oh, and welcome to DF!

 

I just made a post about a mpg issue im having....im getting anywhere from 10.5-12 right now and i have a 08 4 door hemi.

 

You are right in that the dealer won't find anything. All hooking up to a computer is gonna do is read codes. If you ain't popping a code, they are gonna tell you nothing is wrong.

All the normal MPG robbers shouldn't be hitting a truck with only 13k miles on it. Dirty TB, EGR, bad plugs, wires, etc shouldn't be a factor at all.

But don't let the dealer blow smoke up your a$$, there is a problem there, you are getting way worse gas mileage than comparably equipped Hemi's. Hell, the old 5.9 Magnum "Pig" does better than what you are seeing...

 

have them check all the wheels spin easily too. lift it and spin the wheel, it should spin easily and continue spinning for a bit. it'll help rule out bearings.

on the rear hold one wheel and spin the other. it will be harder because by doing that you are spinning the diff and the driveshaft and *** end of the trans, but it should spin freely and without drag.

 

What all have you done to the truck? Is it all stock or have you modified it any (larger tires/bigger rims)? Hows your tire pressure? What climate do you live in? I always get worse mpg when it get cold out vs in the summer. Also do you have a winter blend and summer blend gas where you are at? Before I really started modding my truck, driving at anything over 75mph I could watch the needle on my fuel gauge drop. Right now I usually get the best mpg right around 70-75mph or 2200-2300rpms.

 

My old 2nd gen had that problem. Really hit the MPG's hard until I realized what was going on and fixed it.

 

Offroadteacher...i really like your truck, I want mine to look like that eventually. My mustang had that same them going and looked sick.

Anyways, only mods on the truck are the performance MOPAR dual exhausts. THere is a fiberglass Tonneau as well. Tires are teh stock 20" wheels.

I filled up a few days ago with Hess 87, so we'll see how that goes with half vpower and half 87.

If the brakes were dragging, wouldnt I be gettin a lot of brake dust and wouldnt the brakes be smellin/smokin? I would think they would be wearing out really quickly too.

Whats teh deal with the cold reset? Should I do it? if so, how?

 

Try running another brand of gas. I've heard on here that some guys don't have good luck with Shell. I use BP only. Maybe you could try BP, Mobil or Sunoco? I know when I've run other fuels that my mileage has dropped in the past. Just a thought.

 

May as well try the reset, either pull off a battery cable and let it sit for a while or open your fuse box and pull the PCM B+ Power Fuse, it will be labled on the underside. If you are going the Fuse route, after pulling it out, go into the truck shut the door and turn the key to run (dont try to start the truck) and wait about 5-10sec or so till you hear ding, when I do mine I have to wait about 10sec or so and I get 3 "dings", after that turn the key off, put the fuse back in the correct place and you're good to go. For the first few miles drive how you usually drive, just dont floor it or rev it up to hear your exhaust (if you can) and that should help a little....

If I were to put money down on it the few things I would think that would cause this after going through the posts would be:

Driving style
Type/octane of gas
Tire pressure
Outside temertature
The MDS system not working correctly
Behind on tune ups

Just curious now that I think of it, did the previous owner keep up on all the maintenance? I know you mentioned they babied it, but that doesn't mean that it is up to date with everything.

Also, for highway cruising with the mds on, doesn't it only work up to 65mph?

 

Thanks man.