Why is the inside of the exhaust pipe a bit black?

[EdenAnn]

The reasons for the blackening inside the exhaust pipe are: 1. Poor fuel quality: Inferior fuel quality not only leads to incomplete combustion but also causes carbon deposits to form in the engine. Under ideal conditions, an air-fuel ratio of 14.7:1 ensures optimal combustion, minimizing pollution emissions; 2. Poor driving habits: Such as frequently accelerating abruptly or driving at idle speed, or often leaving the car idling with the air conditioning on. While a blackened exhaust pipe is not a disease itself, long-term carbon buildup can damage the engine, increase wear, and reduce power. Regular maintenance of the fuel system, intake, and exhaust systems is a good choice to reduce carbon deposits and lower exhaust emissions.