White Paper - Cold Flow Diesel Fuel Packages: Protecting Equipment When Temperatures Drop

January 5, 2018 | Dr. Bernard C. Roell, Jr.

Choosing the appropriate cold flow additive is critical to ensuring that your diesel fuel will operate in cold weather climates—regardless of the source of fuel.  Using a properly formulated cold flow diesel additive package formulated for light, middle, or heavy fuel with/without biodiesel could be the difference in your equipment operating in cold climate conditions.

Diesel fuel is a complex mixture of small to large hydrocarbon molecules.  These molecules can be straight chain, cyclic, aromatic or paraffin wax molecules of complex structures.  At above-freezing temperatures, the diesel fuel is homogeneous and works effectively in all regions.  As temperatures begin to plunge, the paraffin wax in the diesel fuel begins to separate, leading to cloudy diesel fuel (cloud point) and the first signs of the fuel gelling.  As more wax settles out, larger crystals begin to form that will inevitably lead to filter plugging. If enough filter plugging occurs, the engine will starve—leading to shut down.

Wax crystals with and without cold flow improver

The only way to keep diesel fuel flowing in cold weather (aside from mixing it with #1 diesel or kerosene—and the penalties in horsepower and fuel economy that come with it) is to add a cold flow improver, or CFI. CFIs keep the wax crystals from sticking together, so they stay small in size and shape, allowing them to pass through fuel filters. The components used harmlessly burn with the rest of the fuel. A good CFI will give you an extra 10-20 degrees of safety net, so your equipment starts more easily and stays running in cold weather.

With cold flow additive packages, you can reduce or eliminate the need for blending with costly #1 diesel or kerosene.  MCC’s CFI additive packages give you the ability to achieve the best performance by lowering the Cold Filter Plugging Point (CFPP), improving Pour Point and improving fuel handling.  Other additives in our premium cold flow improver packages minimize the effects of water contamination and inhibit ice crystal formation with icing inhibitor and dispersant additives, resulting in less engine and fuel system maintenance and down time.

It's important that diesel fuel be treated prior to cold weather and the fuel getting cold, typically at least 10 degrees (or more) above the cloud point of the fuel being treated. These early treatments prevent problems from happening, but they will not reverse the process once the fuel is gelled. If gelling occurs additional measures will need to be taken to get the wax crystals back into solution.

At MCC, we offer cold flow packages that have been optimized to meet your varying needs. Our packages include additives to help with wax modification in light, medium and heavy wax content diesel fuels, some packages contain Wax Anti-Settling Additives (WASA), as well as icing inhibitors to help with diesel fuels that may have ingressed water and prevent icing in the fuel, fuel lines and filters. Contact us today to find out more about our cold flow and other additive solutions to keep your equipment up and running.

Dr. Bernard Roell


Dr. Bernard C. Roell, Jr.

Dr. Roell is the Technical Director at MidContinental Chemical Company, Inc. (MCC) and has over 20 years of extensive experience in the specialty chemical industry. Dr. Roell can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

MCC manufactures and distributes petroleum additives that enhance the performance of fuels and lubricating oils in vehicles, equipment and machinery. MCC provides comprehensive additive solutions to provide customers with performance advantages from the most advanced additive technology available today.