[carsluTT]

i changed my fuel filter about 2,200 miles ago and also did a oil change. everything seeemd the same after word for about 1000 miles and now i have had my milage drop a good 5mpg. i dont get it could my filter be cloged in that short of a time span? its been realy cold for at least a month here in CO, could the extra cold weather cause my fuel milage to drop? i have tryed diffrent fueling stations to see if i was just geting some bad fuel and that didnt make any diffrence. im realy starting to wonder what is going on. i havnt changed any thing about my truck since i did my last service. what gives?

thanks

 

[WYOMAX]

My Milage has gone to HE!! to I dont know if it is the new diesel mixed with the winter fuel or what but I am lucky to get 12 MPG now. I am sure the below zero temps art helping much eather!!!

 

[Blue Max]

Do you have your winter covers on so the truck will warm up? It make a big difference on my truck.

 

[carsluTT]

i have no winter cover, didnt think it would help but if u say it will i guess ill find one and test it out.

 

[Blue Max]

Diesels run better with some heat in them. Just throw some cardboard over the front and do a test.

 

[firetech7459]

My mileage is always worse in the winter, but not by 5 mpg. Seems like I'm always leaving it running so I have a warm truck.

A sudden drop in fuel mileage could also be a symptom of an injector leaking. you might want to send out an oil sample or do the paper towel test to see if there's any diesel in your oil.

 

[StevenE]

firetech7459,
What is the paper towel test?

Steven

 

[carsluTT]

yeah paper towel what.?......

 

[Kurt W.]

Not for certain but I think if their is a ring around the oil you place on the paper towel it means you have diesel fuel in your oil.

 

[firetech7459]

I've only read about the paper towel test here, but essentially Kurt is right. You take a drop of oil from the crankcase and drop it on a paper towel and if you see 2 concentric rings, the inner one will be oil and the outer one will be fuel because of the lighter viscosity. If there's no fuel in the oil, you should only see one ring, I've never tried it though. A search will get you better info.
When I was having injector issues, I sent off an oil sample so that I would have some hard evidence if the dealer tried to shrug me off.

 

[Max Owner]

Winter fuel and cold will cause a fuel milage drop.

Maybe the new low sulphur diesel could be affecting milage?