Diesel particulate filter
A diesel particulate filter (DPF) is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine.
Diesel particulate filter of a school bus
A diesel particulate filter (top left) in a Peugeot
Off-road - DPF installation
Cordierite Diesel Particulate Filter on GM 7.8 Isuzu
Diesel exhaust is the gaseous exhaust produced by a diesel type of internal combustion engine, plus any contained particulates. Its composition may vary with the fuel type or rate of consumption, or speed of engine operation, and whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application.
British Rail Class 55 Deltic diesel locomotive with their characteristic dense exhaust when starting a train.
A diesel engine that operates below the smoke limit produces a visible exhaust. In modern motor vehicle diesel engines, this condition is generally avoided by burning the fuel in excess air even at full load.
Heavy truck, with visible particulate soot.