Diesel Winter Mileage

[idaho04]

This will be my second winter driving my 2006 Dodge Cummins truck. I get a great mileage (~22 mpg) but I noticed that it gets worse in the winter (~20 mpg). I was thinking of two possible reasons: 1) engine running colder or taking longer to warm up, 2) winter diesel here in NoID containing anti gel chemicals.

Anyone has an explanation?

[RonL]

Winter diesel is usually a mixture of #2 diesel and #1 diesel. #1 diesel has less energy per unit of volume, thus, less mileage. Winter mix is, essentially, "thinner".

RonL

[dubba]

Also if you regularly fill at an unbranded/off brand station be sure to ask someone in the know what the mix is. At a station near me I noticed that whenever I filled at this station in the winter I lost mileage. It turned out they were running a 50/50 mix thinking that was better.

[Pat]

Frequently #2 diesel is mixed with kerosene to lower the gel temp. The moix has less "umph" per gallon and so you burn more of it to git 'er done.

I don't know if anti-gel additives have that much impact on mileage. I can't promise you that commercial sources of fuel add anti-gel. I can assure you that "winter fuel" is #2 mixed with lighter fuel (kerosene or #1 or...) and that it has less energy per gallon.

Don't worry about the reduced mileage as it is just a normal result of the "weaker" fuel and is NOT due to a problem with your equipment nor does it pose a problem for your equipment. It is just a fact of life that you will be charged full price and get less energy per gallon.

Longer warm up periods and other winter effects don't help but the major contributor is the fuel modified to reduce the cloud or gel temperature. Having fuel turn to jelly in the lines and tank is much more of a hassle that paying 10% extra to avoid it.

Our Prius also suffers a considerable dip in mileage as temps fall in winter. It runs the ICE more to keep it warm when it would not otherwise need to run it as much.

I know we will get winter but today it is 81F in OKC and south central OK.

Pat