The Mazda BT50 diesel particulate filter works like any other. It uses a ceramic material that forms a honeycomb structure to trap any soot that has been emitted by the engine. This soot is then burned off at high temperature, turning it into a harmless ash. This process is called ‘DPF regeneration’ and can either be an active or passive process.
Passive regeneration relies on the car being driven over 60km/h. Driving at speed for lengths of time results in naturally hot exhaust gases which are used to burn off the soot that has been trapped by the DPF.
Active regeneration is required when the vehicle is not able to maintain this speed, and so heated exhaust gases have to bypass any cooling and go directly to the DPF to burn off the soot. This method is relied upon for inner-city diesel cars that don’t usually have the opportunity to sit at higher speeds for longer periods of time.