Biodiesel can be used in pure form (B100) or may be blended with petroleum diesel at any concentration in most modern diesel engines.

Biodiesel has different solvent properties than petrodiesel, and will degrade natural rubber gaskets and hoses in vehicles (mostly vehicles manufactured before 1992), although these tend to wear out naturally and most likely will have already been replaced with FKM, which is nonreactive to biodiesel.

Biodiesel has been known to break down deposits of residue in the fuel lines where petrodiesel has been used. As a result, fuel filters may become clogged with particulates if a quick transition to pure biodiesel is made.

Therefore, it is recommended to change the fuel filters on engines and heaters shortly after first switching to a biodiesel blend.