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, roadtransport.com 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.