Nearly 20 years ago the world truck manufacturers embarked on a program of reducing the emission levels of trucks.

In Europe the EURO standard started in the early 1990s as EURO 1, today it is EURO 4, and moving to EURO 5.

Australia has harmonised its emission standards with the EURO standard.

However, as Australia imports trucks from North America and Japan, we have also adopted the North American EPA standards, and Japan standards. Currently trucks sold in Australia meet either the EURO 4, US EPS 2004 or Japan 05 long term standard. All these standards are of similar stringency.

In the past 20 years more than 90% of the toxic emissions of diesel exhausts have been removed, whilst engine power and economy have improved significantly.

There are two methods of reducing toxic emissions.

Exhaust Gas Recirculation (EGR) which reduces combination temperatures and the formation of NOx.

Selective Catalyst Reduction (SCR) which uses ammonia and demineralised water to reduce NOx to harmless nitrogen and water vapour.