When and Why to use Anti-Gel Diesel additives

To prevent diesel fuel from gelling (or crystallizing) you should use an anti-gel fuel supplement. Anti-gel additives are easy to use. Just pour them in your fuel tank. Anti-gel additives drop the freezing point of diesel fuel so that it is less likely to freeze in cold weather. The reason to add additive to diesel is because diesel fuel contain wax. The problem with the wax is that this is what causes the fuel to gel, and gelled fuel can block filters. If the temperature is low enough, it will cause the engine to completely gel up. The reason wax is in the fuel is because it gives the fuel a good cetane value. Wax content is lower in the winter but remains in diesel blends for cetane. The cetane number (cetane rating) is an indicator of the combustion speed of diesel fuel and compression needed for ignition. It plays a similar role for diesel as octane does for gasoline

So, when should you start adding anti-gel additive to your diesel?

  • When temperatures are below freezing (32degrees F)

    It is always smart to start using anti-gel as soon as temperatures approach freezing. The rule of thumb is that the lower the temperature, the more fuel additive needs to be added. Best suggestion is to follow the instructions on the bottle of your anti-gel.

    • Rapid drop in temperature

      If the weatherman is anticipating a cold front, you are better off adding more anti-gel additive in preparation. Preparation is key. Anti-gel additives will not damage your engine.

      • When you add fuel

      Use an anti-gel additive whenever you fill up with diesel in the winter. Most additives can be added before or after you add fuel. However, if you add beforehand you can ensure good mixing.

      • When your fuel begins to gel.

      Add an anti-gel additive as soon as possible. If your fuel is already gelled or your fuel lines are clogged up, use an emergency additive that de-thaws the fuel and de-ices the filters. The emergency treatments re-liquify fuel so it can be combustible again.

      Did You Know?

      Adding anti-gel diesel fuel additive to a gelled diesel fuel tank will not de-ice your fuel tank and help in starting your engine. Most diesel anti-gels cannot be added to the fuel tank once the fuel reaches a gelled stage. You need to treat the tank with a de-icer additive to get the fuel flowing. Anti- gel additives need to be added to the tank no later than 10F degrees before the cloud point of the fuel to ensure proper mixing of the additive. De-icers should be poured into the filters and tank. Then wait a minimum of 30 minutes before starting. Anti-gels need to be mixed into the fuel and not poured in on top of the fuel otherwise they will not mix properly. Warm fuel is the ideal additive mixing conditions.