Fuel Filter Clogging Faster
B40 biodiesel contains a high level of FAME (Fatty Acid Methyl Ester), which is hygroscopic (absorbs water from the air). This property affects the fuel’s stability and reduces its quality. Water in the B40 tank promotes bacterial and fungal growth, forming deposits and dirt that clog the fuel filter. When clogged, the flow of B40 to the engine becomes unstable, causing loss of power or engine failure.
Engines Get Dirty Faster
Biodiesel deposits in B40 can form carbon buildup on injectors and combustion chambers. Over time, this leads to faster engine contamination, reduced performance, and thicker black smoke emissions. Regular cleaning of the fuel tank is required to prevent deposits from damaging the injector.
Higher Fuel Consumption in Certain Engines
Not all older diesel engines are designed for high biodiesel content. For older models, using B40 can increase fuel consumption since B40 has lower calorific value than fossil diesel. To generate the same power, the engine must burn more fuel per liter, making it less efficient.
Reduced Engine Performance
Sludge and slime in the fuel system can block B40 flow to the combustion chamber. In vehicles, this causes reduced acceleration and power, especially in heavy-duty trucks, long-haul buses, and heavy equipment used in mining. Gensets running on B40 may also face difficulties starting if maintenance schedules are not optimized.
Low Fuel Stability
B40 biodiesel degrades faster during long storage due to oxidation. The fatty compounds in biodiesel react with oxygen, heat, and light, accelerating oxidation. After 2–3 months, the fuel quality can decline, especially with poor storage conditions, increasing the risk of hard starting in diesel engines.
