European emission standards for truck and other heavy-duty vehicle diesel engines are normally known as Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI. Starting with Euro 1 standard in 1992 the main aim was to reduce pollution and in turn improve air quality within the EU.
Euro I standard was introduced in 1992. Euro II standard followed in 1996. Both these standards were voluntary and were not enforced.
Euro III standard was introduced in 1999. This introduced a separate nitrogen oxide limit.
Euro IV standard was introduced in 2005.
Euro V standard was introduced in 2008
Euro VI standard started in 2013/2014
European emissions standards in trucks are the set limit of maximum values of harmful emissions that are allowed to come out of the exhaust. To fight pollution and for reasons such as health and air quality, the regulated emissions are:
- Oxides of Nitrogen
- Particulate Matter
- Hydrocarbons
- Carbon Monoxide
- Ammonia
Euro 4 and Euro 5 standards have mainly concentrated on reducing particular matter and oxides of nitrogen emissions. These trucks would normally have emissions control system consisting of all or two of below components:
EGR (‘exhaust gas recirculation’ this will reduce Oxides of Nitrogen emissions by adding cooled exhaust gas to intake air)
SCR (‘selective catalytic reduction’ system, this will reduce Oxides of Nitrogen emissions by adding ammonia (adblue) to exhaust system)
NOX (‘oxides of nitrogen’ nox sensor removes oxygen and breaks down the nitrogen oxides to provide a reading, this reading is then sent to truck’s SCR system which can then adjust itself to reduce NOx levels)
Most common combination in Euro 5 trucks is SCR + two NOx sensors.
Euro 6 is obviously is the most complex emission control system to date. Some manufacturers claim it offers a range of ecological advantages such as up to 99% reduction in particulate matter, up to 97% reduction in Oxides of Nitrogen and other emission reductions.. This comes at cost, Euro 6 SCR, Nox or DPF systems are extremely expensive to repair and unfortunately not as reliable as one would hope for.. Other potential downsides would be Euro 6 trucks will consume more adblue and some fleets have reported higher diesel consumption as well. To put it simply, Euro 6 trucks have the most stringent emissions control system to date, but this most certainly come at a price of much higher maintenance cost.
Euro 6 truck emissions system normally consists of three or all 4 components below:
EGR (‘exhaust gas recirculation’ this will reduce Oxides of Nitrogen emissions by adding cooled exhaust gas to intake air)
DPF (‘diesel particulate filter’, this will filter out soot particles from engine exhaust gas, when filter is full it will increase temperature to burn soot out, this process is known as ‘re-generation’)
SCR (‘selective catalytic reduction’ system, this will reduce Oxides of Nitrogen emissions by adding ammonia (adblue) to exhaust system)
NOX (‘oxides of nitrogen’ nox sensor removes oxygen and breaks down the nitrogen oxides to provide a reading, this reading is then sent to truck’s SCR system which can then adjust itself to reduce NOx levels)
So far Euro 6 is the latest and most advanced emission standard in trucks. Nobody is yet talking about Euro 7 standard, and no manufacturer has announced any dates as of yet. It is very hard to predict when will the new Euro 7 standard arrive or what will it be like..