Johnson Matthey Continuously Regenerating Technology (CRT®) System reduces PM, CO and HCs from diesel emissions and utilizes engine NOx to oxidize soot collected in the filter.

Typical CRT® System reduction efficiencies

Pollutant Reduction
PM > 85%
CO > 80%
VOC > 70%


Every CRT® system is equipped with the CRTdm diagnostic module and data logger which provides extended data logging capabilities. The Soot AlertTM Monitor is an optional product that will alert the engine operator when regeneration of the diesel particulate filter is required.

Johnson Matthey first launched the CRT® system in 1995 with CRT® systems retrofitted to buses in Sweden. Since then, millions of CRT® systems have been installed on on-road and off-road vehicles and equipment, as well as stationary engines which range in power from 40 kW to 4 MW. The development of the CRT® technology earned the Johnson Matthey team the Royal Academy of Engineering MacRobert Award 2000, in recognition of an outstanding innovation to benefit society. 

Read more about the history and development of the Johnson Matthey CRT® technology at:


Learn more about the CRT® System