Today's Trucks are Greener
Around 20 years ago, the world truck and diesel engine manufacturers embarked on a program of reducing the noxious emission levels of trucks. The key emissions that are focussed on are Nitrogen Oxides (NOx), the primary contributor to "acid rain" in urban areas, and Particulate Matter (PM), a known carcinogen in sufficiently high concentrations.
The Europeans began regulating heavy vehicle emissions with "EURO1" in the early 1990s. This has progressed to the current "EURO5", while a very stringent "EURO6" standard become mandatory in the EU from 2013/14.
Australia has harmonised its heavy vehicle exhaust emissions standards with the EURO standard.
However, as Australia imports trucks and diesel engines from North America, Japan and potentially other markets, we have also adopted the North American EPA standards, and Japan standards. The current Australian Design Rule covering exhaust emissions is ADR 80/03, which became mandatory for trucks built after 1 January 2011. ADR 80/03 allows compliance to either EURO5, US EPA 2007 or Japan New Long Term 05 standards. All these standards are of similar stringency.
There are two common methods of reducing toxic emissions to comply with ADR 80/03:
(1) Exhaust Gas Recirculation (EGR), which reduces combustion temperatures and the formation of NOx in the engine, combined with a Diesel Particulate Filter (DPF) in the exhaust system. Most DPFs are capable of filtering up to 98% of the PM produced by the combustion process.
(2) Optimised Combustion to minimise PM, then a Selective Catalytic Reduction (SCR) system in the exhaust, which uses a solution of ammonia and demineralised water (marketed as AdBlue) to reduce NOx to harmless nitrogen and water vapour.
Almost all ADR80/03 compliant engines use one of the methods described above, however some engines can meet EURO5 standard without adopting either EGR or SCR systems. As we progress to the next ADR for exhaust emissions in the second half of this decade, it is likely that most diesel engines will adopt combinations of technologies described above.
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.
It should be noted that a number of TIC members are already offering Euro 6 (or equivalent) compliant trucks in Australia in 2016, this is well before any formal decision has been made by the Australian government to mandate these more stringent emission standards.