Transitioning to Biodiesel Blends
Making the initial change from petroleum-based diesel fuel to a mixture of petroleum-based diesel and biodiesel, commonly called biodiesel blend, has caused some concern relative to short fuel filter service life. If you have experienced this, don't panic.
Biodiesel blends ranging from 2% biodiesel and 98% petrodiesel (B2 blend) to 20% biodiesel and 80% petrodiesel (B20 blend) are common in the market today.
Biodiesel has solvent properties. In some blends containing higher biodiesel content, these solvents will clean the fuel delivery system.
As a result, the broken-down deposits from within that delivery system (varnish, etc.) will get caught by the fuel filter, eliminating the chance for them to move past it and damage expensive fuel system components. This is a good thing and is what the filter is designed to do.
Dependent upon the overall cleanliness of the fuel system (storage tanks, fuel lines, etc.), several filters may need to be used before the system gets completely cleaned up. Once the initial clean-up is complete, you can expect to return to normal fuel filter service intervals.