The European Department of Environment, Food and Rural Affairs (Defra), plans to retrofit SCR systems to pre Euro-5 vehicles for achieving EU set standards, reports.

DEFRA wants some more time for reaching nitrogen oxide (NOx) air quality limits set by EU for 2010.

According to the website, for a five-year extension, it needs to provide details on initiatives that will help reduce NOx emissions. One such proposal for achieving the targets is retrofitting emission-reducing equipment to HGVs.

According to Mercedes Benz press officer Simon Woods, this process would involve changing diagnostic systems, injectors and fuel lines in the vehicles.