Runnin M

This weekend I towed my stock trailer 7 hours to deer camp and here is what I found:

Trip to deer camp: From 3,200 ft to 4,500 feet. Averaged 15.5 MPG (this is from the overhead computer as I pump out of my own tank and don't know how many gallons I use so am unable to hand calc)

Trip back home: MPG dropped from 15.5 to 11.8 (there was a slight head wind for 1/4 of the trip. Also, I changed my air filter after about 2 hours of driving and the MPG continued to drop.

Any ideas? Thanks in advance!

030303

How long since you last changed the fuel filter?

tomm

Did you fill up at the far side?
I've noticed my mileage dropping since the last fill up at $2.69 a gallon which is cheap around here and made the truck run really rough.

I'm just thinking junky fuel makes a big difference.

I've swapped fairly dirty air filters for clean and noticed no mileage gain or loss.

030303

When do they bring out the dreaded winter fuel?

Runnin M

I had my fuel filter changed about 10 days ago when Dodge did the roll over valve recall.

I did fill up at a service station twice after getting to deer camp and I did wonder about bad fuel; however, the engine seems to be running okay.

stock03

You need to hand calculate. My over head is sometimes off by as much as 3 or 4 miles. I don't know what's up with it. I use the over head for the timer only.

Diesel Avenger

Could it be the ULSD?? I have been using it all week in my big truck and have noticed a definite drop in mileage. Maybe two mpg or so. When you don't get but 8 mpg avg to start with, it gets noticed quickly. FWIW, I'm running a 3176C CAT with that junk in it.....I am not liking it at all. I thought maybe it was just my truck, but then my other one was using it last week and it had the same drop. It has a M-11 Cummins, so it just isn't a CAT thing. I sure hope this isn't what the future will hold for us with the ULSD.

Peterbilt

Loosing a couple of mpg in a big truck adds up fast.

Pete

BigDave12768

Did you buy fuel in the mountains? If you did. It's called the winter mix

bluebull

You also have to reset the trip computer everytime you fill or it will not be acurate between towing and nontowing. If you do not reset trip computer it will become more acurate the more tanks you use but only if they are all towing or all nontowing.

Nitro71455

Where did the fuel come from that you "Pumped from your own tank" into your truck?

Runnin M

The low MPG tank came from a station that was located at over 4,000 ft above sea level.

I get the fuel for my own tank from a fuel company in Prineville, OR (they come and fill my storage tank for me).