Why is the exhaust pipe of a new car turning black?

[McAna]

The reasons for a new car's exhaust pipe turning black include: prolonged idling during warm-up, poor air quality, and the combination of direct fuel injection with turbocharging. The symptoms can be exacerbated by the use of low-quality gasoline, oil burning, or a faulty catalytic converter. A blackened exhaust pipe is not directly related to carbon buildup in the car. For a new car, the blackening may be caused by incomplete combustion of gasoline, or the use of low-quality or mismatched fuel grades. Methods to slow down the blackening of the exhaust pipe include: regular car maintenance, periodic inspection and replacement of spark plugs, regular cleaning of the catalytic converter, minimizing high-gear low-speed driving, reducing idle time, and frequently cleaning carbon deposits from various parts of the engine.