diesel exhaust

Diesel exhaust is the gaseous exhaust produced by a diesel type of internal combustion engine, regardless of the fuel type or rate of consumption, or speed of engine operation (e.g., idling or at speed), and regardless of whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application. The physical and chemical conditions that exist inside any such diesel engines under any conditions differ considerably from spark-ignition engines, because, by design, diesel engine power is not controlled by the air/fuel mixture (as in most gasoline engines), but rather it is directly controlled by the fuel supply. For instance, diesel engines generally produce 28 times less carbon monoxide than gasoline engines, as diesels burn their fuel in excess air even at full load.