Q: Winterized Diesel

[JCL]

Standard summer diesel (#2) will gell at around -12C (from memory, based on our local diesel fuel here - it may vary regionally). 12 below freezing in C is about 20 below the freezing point in Farenheit, so that is 12 F (give or take). Once it jells, you need to heat it up to get it pumping again, often by parking in an enclosed and heated garage.

Winter diesel is produced by either blending #2 fuel oil with #1 (stove oil) to thin it out, lowering the temperature at which it gels, or it has other additives included to maintain pumpability at low temperatures.

It is important because you can get stranded if you take a vehicle with summer fuel into a very cold climate. Usually, it burns off on the way there, but it is worth being aware of. The other issue to remember is that winter diesel usually has less heat content (volumetrically) so you will get lower mileage than on summer fuel. They don't typically give you a break on the price, however.

If you live in a cold climate, your local fuel suppliers are varying the diesel automatically (it is bad for business when cars can't make it off the fuel station forecourt). All you will notice is increased fuel consumption during winter.

To the OP, you can always throw a can of fuel treatment in the trunk. I would go with a half tank and fuel up on the way, myself.