Honestly not what you want to hear, but that's probably right for this time of year. Not sure where you are geographically, but colder months use more fuel. The longer it takes to warm the engine, the longer it takes to achieve your best MPG's. Also, winter grade gas, as stated above, can be detrimental on MPG's in a thirsty engine.

The 5.9 is not known for good gas mileage. When it was in production gas was somewhere around $1/gallon. There's nothing more you can do to increase mileage enough to see a significant gain. If you can't afford it now, it may be time to trade it for something more economical. Don't feel bad, I'm in the same boat with mine, and I average around 17 mpg's. Still with the work commute, and high gas prices, a new baby, new house, I can't afford to keep filling up the truck...

 

Yeah, I'd guess that means you have the dreaded "death flash"... And I agree with you, the 5.9 is like the Warthog (A10 Tank Killer) is slower than ****, burns fuel like crazy, but with just marginal care will last forever!!!

 

That's why my truck only has 7600 miles on it and i've owned it for almost 2 years now.
I purchased a beater car initially (dodge stratus 4cyl 5spd...33mpg)
Between the initial cost of the car($600 at auction+ $100 invested) and insurance(basic $130/yr), I was still able to start pocketing money after just 3 months of use. That is how much gas I was using when i first bought my truck. that means that the car paid for itself in just 3mo. Meaning it was free to drive after that and I had something to show for rather than more mileage on my truck and burnt gas that I can no longer use.
Def something to look into, because I was burning $800mo worht of gas if i was driving my tuck. Instead i only paid $250 and the miles didn't go on my truck for silly running around.

 

Thank you everyone for your input so far! Reading through my manual my engine doesn't have an EGR valve so that's one performance robbing piece of junk out of the way! Where can I get Sea Foam? I know I can get it online but I was wondering if I can get it localy at say Advance Autoparts, Autozone etc.? Mind you with my MPG it would probably be cheaper to get it posted from China!!!

 

Any auto parts store, Wal Mart, most small engine repair shops, a few convenience stores, marine shops and even a few grocery stores will carry it.

I do a treatment once every 15k miles when I clean the TB., except the fuel, where I add it at oil change time. It lives in my gas cans for my small engines and boats as it is also a fantastic fuel stabilizer...

 

I have found some in my local Advance Autos. Thank you.

Would one of these help?

http://www.hughesengines.com/Index/p...2&partid=24768

 

That's very expensive. Look somewhere like www.moesperformance.com or www.airram.com. Might find some better prices.

 

I am getting 11.5 to 12 with my 5.9 even with the 35" tires!! SC tuner is your friend!!!

 

Thank you! I know the SCT is expensive but the difference between 8.5MPG and 11.5 - 12MPG The tuner will pay for itself within a few months! Before I talk to Hughes will it override the 'Death Flash'? I just want to be 100% sure.

 

from what ive heard from other people, the SuperChips tuner is the way to go for the 5.9s.

and i used to have a 5.9 in my durango, avged about 9-9.5 mpg in town.