Don't know which gas station your using, but try another one. I've noticed here in Vegas, there can be a pretty big swing in mileage just by using "X" station vs "Y". It can be the same gas company, but if something is wrong with their tanks, can cause bad mpg.

Sam's Club, Costco, Flying J and Sinclair run the best in the Durango (and all about the same price). Chevron and shell are next, adbit a 1-3 mpg hit with higher cost. Arco and others flat out suck.

Outside of Vegas, Chevron is fine. Not sure what it is about this town with chevron, but it doesn't run the same vs elsewhere.

 

Going on a 300 mile trip tomorrow and weather here is pretty cold. Will check mileage for you probably driving at 60mph.

 

Mileage about 18 at 55 to 60mph air temp -6F to -2F
87 octane fuel.

 

Recommended octane varies on elevation I run 87 at 4000'.

 

I have heard that ethanol is not good for them though.

 

Ethanol isnt good for ANYTHING except for lining the pockets of the farmers growing the corn.

 

Just sharing my experience.

2013 1500 4x4 CC with 3.55 and 6 speed trans gets 15.8-16.7 depending on driving habits. 30 miles to work each way mostly highway. I don't baby it or drive it like I stole it.

 

I have a 2009 1500 Sport and i'm struggling the same as the OP. I have yet to see it get over 13 mpg. The day I bought it, I filled it up and drove about 65mph on a calm day. It got 12.5mpg. I'm filling it up about every 200 miles and averaging anywhere from 9-11mpg right now.

 

How many miles are on the truck... new plugs... air filter...??? What gas are you burning...???
Considering its winter time in most locations, fuels are blended this time of year... you`re not going to get the best mpg right now no matter what you do. The best thing you can do is change your driving habits to help you obtain better mpg. Do you start your truck and let it warm up... are you running the heater a lot...??? All things considered, mpg suffer terrible during winter time. Try to keep the ECO light on as much as you can and stop looking at the EVIC MPG meter. If you`re running aggressive snow tires, that alone robs your mpg. Coast as much as you can... it DOES help, believe it or not. Your mpg WILL come up higher heading into summer.

 

It has just over 91000 miles on it. I'm not sure on the plugs since I just bought it within the last month or so but it does have a brand new air filter and a K&N intake sitting here ready to put in. I've got a friend that's a mechanic and we're actually going to go through it this weekend, i'll make sure we double check the plugs. I'm burning 87 for fuel. I do start it up before I leave but usually for about 15 minutes or less. The heater is on just because it's cold out. I don't have an ECO light. I am running 10 ply tires (i do occationally pull a horse trailer during the summer) that are all terrain but not snow tires. I am a nice driver. I do coast when I can and I don't rod around. When on the highway, it never gets over 70mph. I had a 5.3L GMC with 4:10 gears in the rear and 120000 miles, and that thing was getting 20mpg down the highway driving the same as I am now. I knew the dodge wouldn't get that high but I wasn't expecting it to be as low as it is. Right now I have 188 miles on my tank and its says its got about 40 miles to empty. It's been mainly used for highway miles. Maybe about a 70/30 split.

I really hope it starts coming up...its too expensive to drive it anywhere right now.