lube oil. When biodiesel leaks into the crankcase, it has more problems than with more traditional fuel. The biodiesel has a higher boiling point than regular fuel and is less likely to evaporate out causing it to stay in the crankcase for a longer period of time. Also, the longer that the biodiesel stays inside of the crankcase, it degrades the organic acids in the lube oil and then reacts with the crankcase wall. After reacting, it causes deposits of the reacted biodiesel in the walls of the crankcase . There are ways that these effects can be reduced. Chevron created additives to reduce the effects of the biodiesel. See also Oil analysis Wet stacking References Engine problems