With frigid temperatures approaching, now is the time to check your fuel system to prevent common issues and keep equipment running smoothly through cold winter months.

Pete Probst, biodiesel specialist with the Illinois Soybean Association (ISA) and Indigenous Energy, provides five steps to help ensure trouble-free fuel performance this winter.

1. Measure cold-weather operability. Diesel fuel performance in cold weather can vary based on crude oil source and how the fuel has been refined and blended. Cold-flow properties of biodiesel can depend on the feedstocks used for its production.
   
   Whether you run on biodiesel or standard No. 2 diesel fuel, two cold-flow measurements are critical: cloud point (CP) and cold filter plugging point (CFPP). CP is the temperature at which wax crystals first appear in the fuel, making it appear cloudy or hazy. CFPP is temperature at which larger wax crystals form and start to plug the fuel filter.
   
   “CFPP generally indicates the lowest temperature for vehicle operation,” Probst said. “To prevent engine power loss, CFPP should be above expected wintertime low temperatures in your area. Ask your fuel supplier for assistance in testing your fuel before winter begins.”
   
   To test cold-flow characteristics, ISA collected fuel samples from 149 Chicago-area retail stations during the 2017-18 winter. CP and CFPP results were similar for both biodiesel blends and diesel fuel, indicating drivers could expect similar wintertime performance.

2. Use winter fuel additives. Regardless of the fuel you are using, it’s important to winterize fuel to withstand expected low temperatures in your area. “Additives help lower the CFPP and improve the flow of both diesel and biodiesel blends during freezing temperatures,” Probst said. “Work with your fuel supplier to determine additive needs and remember to apply additives before the fuel reaches the cloud point temperature.”
   
   Probst noted that drivers traditionally have added No. 1 diesel, or kerosene, to diesel or biodiesel blends to improve cold weather operability. However, kerosene has a lower BTU value than diesel and can reduce fuel economy. “Additives are generally less expensive and perform just as well as kerosene,” he said.

3. Check for contaminants. Whether you run biodiesel or standard diesel fuel, check storage tanks for water or other contaminants. Water is the most common source of fuel filter plugging issues in diesel engines during winter. When temperatures fall below 32 degrees F, excess water in the tank can freeze and block fuel flow through the filter.
   
   A Bacon Bomb device is an easy and inexpensive way to retrieve a fuel sample from the tank bottom, where free water and sediment settle. You can purchase your own Bacon Bomb for sampling or ask your fuel supplier to provide this service,” Probst said.
   
   Place the fuel sample in a clear plastic or glass jar to inspect for water and sediment. The fuel should be clear and bright. Hazy fuel indicates water contamination. If you detect water, take steps to clean and remove it, or consider a de-icer to keep the water suspended and moving through the system during cold weather.

4. Be aware of microbial growth. Water in the tank also leads to microbial growth.
   
   “Microbial contamination has become more common since the introduction of ultra-low-sulfur diesel (ULSD) fuel in 2006. Prior to ULSD, high sulfur content in diesel fuel acted as a natural antimicrobial agent,” Probst said.
   
   If inspection shows water in your storage tank, Probst advises working with your fuel supplier to test for microbes. Biocides are available to treat contaminated tanks. In severe cases, the tank should be drained and cleaned.
   

5. Keep water out of the tank. Take these steps to prevent water from entering your fuel tank in the first place. For example:

   • Top off tanks to eliminate air space that could foster condensation when temperatures change.

   • Keep fuel caps tight to keep water from entering the tank.

   • Inspect hoses and gaskets for leaks.

   • Keep underground storage tank sump pits and fill connection spill containers clean and dry.

“Cold weather performance issues are sometimes falsely blamed on biodiesel blends. In truth, all diesel fuels require maintenance steps in winter. Remember, biodiesel is an all-weather fuel with high performance year-round. With proper maintenance and basic housekeeping practices, you can expect a problem-free experience from ULSD or biodiesel blends up to B-20,” Probst said.

This article was provided by the Illinois Soybean Association.