answersLogoWhite

0

All oil turns black over time. Most of the black comes from small particles that are trapped in the oil. Also, carbon from the incomplete combustion of gasoline is held in the oil. It is impossible to get all of the oil out of an engine unless the engine is taken apart and cleaned. This left over "dirty" oil can cause new oil to darken.

User Avatar

Wiki User

18y ago

What else can I help you with?