You really need to understand the role of the additives. “Glycol ethers, used as directed, can help to minimize the effects of water in a diesel fuel system. But under the strictest definition of contamination, these chemicals actually contribute to water contamination of the fuel phase,” says Harvey. “Some common diesel fuel additives employ small concentrations of alcohol to reduce the freeze point of any water in the system, thereby helping to prevent ice crystal formation and the subsequent plugging of fuel filters.”
Monitor biodiesel blends
Biodiesel blends are becoming increasingly common. Depending on the type of blend used, you may want to closely monitor the fuel for moisture contamination, since some blends can be more susceptible to water contamination.
“Biodiesel blends up to 5% volume are considered to be normal diesel fuel as defined by ASTM D-975, the standard specification for diesel fuel oils,” says Harvey. “Anything above 5% volume may require additional oversight and maintenance to keep the fuel system free of water.”
Of course, whether you use standard No. 2 diesel or biodiesel blends, there is no substitute for good housekeeping practices.