Winter has a way of sneaking up on us and if your fleet is not prepared you can find yourself with trucks stuck in the yard, at docks or at truck stops unable to start.

Diesel fuel is one of the things that is affected by cold winter temperatures. Diesel fuel has water in it, and although fuel/water separators remove a great deal of the water they can’t get all of it. When the temperature drops, the water can turn to ice, which can cause the fuel filter to ice over and prevent fuel from flowing.

Diesel also contains paraffin, a waxy solid that gels when it cools. When diesel fuel gels it cannot flow through the vehicle’s fuel system and it can clog fuel lines and fuel filters.

With diesel fuel there are two key temperatures points to be aware of concern: cloud point and pour point. Cloud point occurs when the dissolved solids in the fuel, like paraffin, begin to separate from the rest of the fuel and form wax crystals. At this point the fuel starts to get cloudy. The pour point occurs when the wax has gelled to a point where it can no longer flow. The pour point temperature is lower than the cloud point by as much as 10 to 15 degrees.

The amount of water and paraffin in diesel fuel varies so there is no one set temperature at which gelling will begin to occur. Generally it can start at about 10°F, but can happen at higher or lower temperatures depending on the make up of the fuel.

Once the paraffin gels it is difficult to get it to reintegrate into the fuel so the goal is to prevent the gelling from occurring. The first step is to check the blend of fuel you are using. As temperatures drop, make sure you switch from summer blend to winter blend diesel. Winter blend fuel is a mixed fuel that contains #1 diesel/kerosene, and it is the kerosene that lowers the gel point of the fuel.  Different areas of the country will have different winterization levels for their fuel so make sure the fuel you purchase the fuel blend that matches the climate you will be operating in.

In extreme cold environments insulated fuel tank blankets will provide additional protection. But the most common way to prevent gelling is to use fuel additives like PEAK C&I Cold Weather Diesel Anti-Gel with Cetane Boost and Injector Cleaner.

This multifunctional diesel fuel additive contains a blend of cold flow improvers that prevent fuel gelling at temperatures as low as -40°F and reduces the Cold Filter Plugging Point (CFPP) by as much as 39°F. The product’s formulation increases cetane by up to four numbers, an additional anti-icing additive reduces filter plugging due to ice build up, and its detergent technology cleans the fuel injectors on today’s high-pressure common rail direct injection diesel engines.