By Paul Nazzaro, Advanced Fuel Solutions, Inc.

Virtually every weather expert in the country is forecasting a long, cold winter ahead. While I can’t predict the weather, I can, to some degree of certainty, forecast whether or not your fleet will experience winter operability issues based on your cold weather diesel treatment and fuel storage strategies. Assuming the weather reports are true, and your diesel holds up with no instances of gelling, icing or equipment failure, I’m guessing your cold weather preparation will have probably looked something like this.

First, you purchased a pre-blended, winterized diesel from a reputable supplier. Established suppliers are more likely to practice good housekeeping (e.g., regularly cleaning storage tanks, using moisture control technology and monitoring/treating for contamination) to prevent the otherwise inevitable degradation of fuel. They’re also more likely to work with reliable additive suppliers who can ensure that the fuel is properly treated at the right dosage, taking the guess work out of it for you, the consumer. While certainly still wise to monitor the performance of your fuel on the road and through periodic fuel sample testing, working with proven upstream suppliers and additive professionals—rather than buying untreated diesel and blending it with an after-market product yourself—reduces your odds of experiencing a costly equipment breakdown in the field. If you do elect to take treatment into your own hands, be sure to consult a treatment professional to ensure the product is applied properly and in accordance with the manufacturer.

Next, you were sure to use a multi-functional winter additive package suited to your particular needs and climate conditions. Is your diesel equipment stored inside or out? Is it subject to extended periods of shutdown? These are some of the questions that can help determine the right additive package for you. Generally speaking, a well-rounded winter additive package will include a cold flow improver, a wax anti-settling agent, a pour point depressant and a deicing compound—though the concentrations of these components may vary from package to package.

The pour point, though not the deciding factor in winter operability, is the lowest temperature at which fuel can maintain its fluidity and continue to flow. The cloud point is the temperature at which wax crystals begin to precipitate out of the fuel, falling to the bottom of bulk and saddle tanks. Once wax does begin to form, a cold flow improver will interfere with the crystals’ growth, modifying their size and shape so fuel can flow freely through filters, or lowering the cold flow filter plugging point. Advanced cold flow additive management relies on wax anti-settling agents to suspend wax that would otherwise precipitate out of fuel during extended equipment shutdowns. This technology works hand in glove with cold flow improvers by keeping the heavy wax from settling to the bottom of the tank, preserving the flow rate of fuel that has been sitting idle. Finally, a deicing compound will prevent ice crystals due to the presence of water in the fuel and in your storage system (waiter is the number one contaminant in diesel) from loading in filters or causing abrasive wear to your fuel system.

Diesel additives are constantly becoming more sophisticated and refined in order to keep up with today’s rapidly advancing engine technology. Winter additives have come a long way since wax modifiers were first introduced in the 1970s. Unless you have a firm understanding of the latest additive technology and diesel operability points, make sure to work with a fuel or additive supplier who does. The proper application of an advanced multifunctional winter additive package—complimented by a vigilant housekeeping protocol—should carry you through even the coldest of cold conditions. With a presumably harsh winter on its way, will your cold weather defense be validated, or exposed?


imageAdvanced Fuel Solutions, Inc. (AFS), based in North Andover, Massachusetts, provides fuel quality consulting services and fuel additives designed to keep fleets on the road profitably. For more information on cold weather operability, winter additives or other fuel quality issues, contact Paul Nazzaro at 978-258-8360 x301 or visit