Where does carbon deposit build-up come from?
Carbon deposit or gunky build-up on critical engine parts is the result of various chemical processes that occur during engine operation. These chemical processes create a residue that consists of carbon particles that can build-up on intake valves and fuel injectors. All Shell gasolines are designed with a higher level of cleaning agents than required by the Environmental Protection Agency (EPA) – opens in new window to prevent the build-up of these deposits.
