well over the last 3 days went from 12 to 11.1 and thats with alot of coasting! oh and i changed the pcv valve (mopar one) last week it was stuck open.

 

down to 10.3 what is going on only thing that has changed is the weather truck must hate the cold cause its killing gas.

 

Do you let your truck warm up at all? Or do you get in, start it up, and drive off?

 

Winter blend fuel combined with the denser air requiring more fuel to hit the magic mixture ratio will do it every time. And if you're still on the performance tune but fuel economy matters enough that you're willing to make a change, drop down to the towing tune. Often, if not usually, the towing tune will deliver better fuel economy on these trucks than the fuel economy tune.

 

I've tired both letting it warm up and crank and go no diffrence. I put the towing tune on last week and filled up and got 150.2 miles out of the tank. my job is only 12 mins away so it doesn't really get all the way up to temp on really cold days which we had here (GA) lately

 

My MPG is also suffering.

I've been carpooling to work lately, usually 3 days of the week, so I only have to drive the Ram twice a week, last week I drove 2 days but put a few extra miles on the truck since I was picking up some furniture, and I do mean a few extra miles, and still it took about half a tank.

Winter mileage has sucked donkey *****..

 

I believe that is too low. I took a trip to MN for Christmas and averaged 15. Most tanks were 16 but one was 12 in South Dakota. Total miles was 3440.

As a daily driver going to work around Everett, I get about 13-14. It's been 45 degrees here so I don't run the heat or defrost as hard.

I have never had to fill up in 150 miles. Even when I moved with my cargo trailer packed full, and floored over mountains in 2nd or 3rd I would get 200 miles before fill-up.

Maybe the gauge is off or bad? When I get to half tank, 180miles means 13mpg, 200 is 14, 220 is 15, and 240 is 16. I've hit 280 per half twice which was 17.9 and 17.4.

When I towed, I would hit 140-150 per half and get another 50 before the light. Typically drove 220 before I stopped. Worst tank towing was 9 best was 11. I just can't imagine getting 10 on a daily basis with an empty truck. That means you get 100 miles at half a tank. There must be something dragging bad. Or the pcm is screwy.

 

Gas mileage contributors:

O2 sensors. (this is a big one. NTK, or Denso, skip bosch.)
Blown plenum?
Other vacuum leaks.
low compression....
clogging cat?
Tire/gear ratio mis-match. (to high a gear for tire size.)
CAD not disengaging. (not a lot of difference, but, some, anyway.)
Other failing sensors. (that won't necessarily set a code....)

 

full tune up done 5 months ago (everything even all fuilds) both 02's replaced 4 months ago (NTK) plenum looks okay no oil bulid up as for vacuunm leaks i have p0442 CEL that i've been trying to locate since i bought the truck 9 months ago and cant find it neather can 3 shops thats done smoke tests so i gave up on that. cat is good. all tires match and psi is the same for all 4:10 gears. I've went thur and replaced alot of sensors cause the others owners didn't do **** to it but drive it from the looks of it all orignal everything. I dumped maybe $1300 in sensors/parts/fulids since i got the truck which was $2600

parts replaced

PCM
PCV valve
02's
gas cap
map sensor
iac sensor
tps sensor
purge sole sensor
thermostat
leak dect pump
fuel filler neck
plugs/wires/cap/dist
all fulids

 

Where you live and your typical drive makes a huge difference in MPG. You can't compare me (northcentral WI) and the guy from SD who don't deal with much traffic to someone in a big city who is stuck idling in traffic 2hrs to go 8 miles twice a day. What is your drive like? Lots of lights, stop signs, grid lock on the interstate, or can you drive to where you're going without really having to stop?

I thought I read a post about the 180 deg Tstat being to cold to agree with the computer, especially in winter. Maybe put a 195 back in it.

Also, a few minutes of warm up every time you use the vehicle in winter, affects MPG more than you would suspect. I'm still wondering about your plenum and catalytic converter though.