Why Is There Black Soot on the Exhaust Pipe of a New Car?

[OSimon]

The reason for black soot on the exhaust pipe of a new car: The black soot is carbon deposits, which is a normal phenomenon. It occurs when the air-fuel mixture is too rich and does not burn completely, especially during cold idle when the engine temperature has not yet risen. At this time, the fuel injector sprays a larger amount of fuel, resulting in a rich mixture that leads to incomplete combustion. Carbon deposits include two concepts: one is engine carbon deposits, which are a coking substance produced by unsaturated olefins and colloids in fuel under high temperatures during engine operation; the other is carbon deposits in electrical discharge machining, which should be avoided as much as possible, especially in precision mold processing, as it can have a fatal impact.