Diesel particulate filters (DPFs) have been fitted to both heavy and light duty vehicles for a number of years. Emissions legislation around the world are becoming more stringent and are focused on gaseous emissions such as nitrogen oxides as well as particulates formed during the combustion process, and it is becoming increasingly important to reduce these harmful by-products through a variety of onboard devices.

Take a look underneath a modern gasoline-powered car and you will see an array of devices attached to the exhaust system that have only appeared in recent years. These are often collectively termed ‘exhaust after treatment devices’ or ATDs. Vehicle manufacturers have been forced to add these expensive devices in order to meet the ever-tightening emissions legislations that are increasingly in place around the world.