Mechanic’s Blog – Winter Anti-Gel Tips

September 22, 2015

It is getting to that time of year when the temperature is dropping and diesels aren’t particularly fond of the cold weather, especially when it gets below 0° F. Treating fuel with an anti-gel should be pretty easy, you should be able to just dump it in and be on your way right? Well almost… Here are a couple of things to remember to properly “additize” your diesel fuel this winter.

Keep your anti-gel stored somewhere protected from the elements until you are ready to add it to your fuel. Room temperature is optimal, but anything above 0° F works. Anti-gels will actually get pretty thick when sitting on their own in the cold, to the point where you could say they have “gelled.” It is just the nature of the flow improvers, once they are in the fuel, they will dissolve and help your fuel to flow freely. For reference, our Hot Shot’s Secret Diesel Winter Anti-Gel has a pour point of -38° F. Once it is mixed with the fuel, that number drops to -65° F.

Make sure to put the additive in when the fuel is above the cloud point. The cloud point is the temperature at which the waxes will start to separate, making the fuel look cloudy. Adding an anti-gel in below the cloud point will negate any benefits the anti-gel has to offer. The cloud point can be anywhere from 0°-15° depending on the quality of the fuel you are dealing with. Even in freezing conditions, an underground fuel tank you are pumping from should be above this clouding temperature (somewhere between 35-50 degrees typically.) If you pour the additive in when you first fill up, the anti-gel can properly mix with the fuel and be effective.

Any research on cold diesel fuel will tell you that it is the wax paraffin in the fuel that causes gelling issues. As the fuel gets cold, these waxes tend to crystalize, and these crystals plug up your fuel filter, leaving you stuck on the side of the road if you even make it out of the driveway. This is absolutely true, but there is a little more to this picture that we should look at. Water. Moisture gets into diesel fuel through condensation, this isn’t something you can avoid. We all learned in school water freezes at 32°, so it too can cause trouble in our fuel filters as the temperature drops. Be sure your anti-gel has dispersing agents in it to take care of the water and help free the system of moisture, like Hot Shot’s Secret Diesel Winter Anti-Gel does.

The last thing you should do is make sure the fuel system is clean at the beginning of the season. There are several contributing factors that can plug a fuel filter prematurely during cold weather. Fuel gets circulated to the fuel injectors, and the fuel that does not get used goes back to the fuel tank. The fuel that gets circulated gets very hot and produces problems such as asphaltines and IDID’s. Cold weather can worsen these problems, and you need a strong detergent like our Diesel Extreme to help clean them out.