A lot of biodiesel customers had trouble with our recent freeze and cold fuel in their cars. With overnight temps in the teens, and over 48 consecutive hours of sub-freezing temps a lot of people’s fuel gelled despite their adding petro-diesel to their tanks. Here are some things to keep in mind:

— When in doubt, add diesel.
In can be discouraging for the individual concerned with sustainability and reducing their carbon footprint to have to burn petroleum in their cars, but unfortunately this is going to be a fact of life this winter with our supply of waste-oil derived biodiesel (keep in mind that the canola-derived bio we have had in the past is unfortunately not available at this time).

The cold hard fact is that a lot of people with too high a blend of bio in their tanks had problems. If you had B99 and you topped off with B80, then you likely had problems because your mix was closer to B90. If you don’t fill up your car very often you need to be aware of what is in your tank.

But you also have to be aware of the source of the petro-diesel. Buy from a high-volume source that stringently filters their fuel, as diesel that isn’t well-filtered, can cause problems for your car..

Adding a winter additive to the fuel helps. It is unlikely that local retailers will have winterized diesel, and using the right additive can make all the difference.

Your best bet is to get fuel from Dr Dan’s, where we have high-quality and well-soured petro-diesel with the correct winter additives. It is available during normal office hours (10 am until 6:30 pm) and a good way to go would be to bring by a fuel can and fill it up so you have some available at home. Keep the can in your garage or basement, somewhere it’s at least a bit warmer than outside. This few gallons to add to your tank can make a huge difference (keep in mind that diesel is not volatile like gasoline, and not dangerous to keep stored)

— 24-hour temps and thermal masses:
As we have mentioned, it is important to keep in mind a little bit of physics and thermodynamics. Your car is a thermal mass, and running your car warms up the entire car, including the fuel system. When your car sits, it starts to cool down, and how long it sits and how cold it gets will determine how big a problem you can have.

What we saw last week were 24-hour average temps barely above 20 deg F, if at all, and once all the heat from running your car dissipated, and the fuel system reached ambient temperatures, there was no way for it to warm up. If your car sat for any length of time without running, there wasn’t enough heat energy, even after temps climbed back above freezing, for the thermal mass of your car and the fuel system to warm up and thaw the fuel.

Cold-weather fuel issues are a function of both TIME and TEMP!

— What to expect.
Forecasts for the coming week call for 24-hour average temps right around 40, which for the most part shouldn’t be a problem. Long-range weather models are calling for an unusually cold winter, however, and it’s probably best if we all heed the warnings from this last week.

Be prepared. Mind the mix in your tank. Pay attention to weather forecasts. None of us want to burn more petroleum than we have too, and its unfortunate that we are in this position, but this is probably going to be the case for this winter.