Bad Fuel, or Something Else?


 Talk of bad fuel is becoming a more common issue on farms, including some in MaxYield Cooperative’s trade territory. But is it really bad fuel, or is something else going on?

“You can’t always tell what’s going on by looking at a fuel sample,” said Chad Besch, energy team leader at MaxYield.

MaxYield’s energy specialists have kits that allow them to pull fuel samples from the bottom of a client’s tank so they can send the sample to a testing lab. In all the samples collected so far, the culprit isn’t bad fuel, but high microbial content in the water.

“Problems inside the fuel tank start with water, since microbes need water to survive,” said Besch, who noted that microbial growth can morph into slime. “Microbes get started on the inside of your tank if the tank isn’t full, and they can live in the area between the diesel and water.”

Microbes Can Make Slime

Water can get into diesel fuel through the refining process, the pipeline distribution systems and condensation in the fuel tank. “You can’t do anything about the first two, but you can address the third issue,” Besch said. “The best way to fight condensation in your tank is to keep your tank full.”

Lower Sulfur Fuel, New Injection Systems Can Create Challenges

Condensation and microbial growth issues aren’t just limited to bulk fuel barrels. They can also impact fuel tanks in your farm equipment like tractors and combines. Once microbes start growing, they can plug your fuel filters and cause injector problems, creating potentially expensive repairs.

It’s easier for microbes to take hold in today’s diesel fuel if any water is present in the fuel. Why? Today’s diesel fuel is much different than diesel in years past due to federal regulations implemented in 2006 that lowered diesel’s sulfur content.

“Years ago, the threshold was 5,000 parts per million (ppm) of sulfur,” said Besch, who noted the threshold has been revised various times through the years. “Starting in 2006, the requirement dropped from 500 ppm to less than 15 pmm.”

“Although the goal was to reduce air emissions, sulfur isn’t all bad. It’s antagonistic to microbial growth,” Besch noted.

The reduction in sulfur isn’t the only factor that has changed in recent years. Consider the debut of the high-pressure common rail systems that are part of injection systems in newer diesel-powered engines. These systems are designed to reduce emissions and boost mileage. The fuel that isn’t combusted comes back to the fuel tank and is warmer when it returns. “With the right atmospheric conditions, you’re prone to create more condensation,” Besch said.

Want to test your diesel or learn more about these options to protect the quality of your diesel fuel? Contact your local MaxYield energy solutions specialist, or call MaxYield’s Energy Central at 515-200-1362 or 866-711-7282.