Effective from October 2006 no new vehicles were registered in EU unless they were able to meet the requirements of Euro 4 as a minimum and effective October 2009 any new registrations will have to be Euro 5 compliant.

In order to meet the demands of Euro 4 & 5 commercial vehicle manufacturers (OEMs) have evaluated various engine development technologies. Resulting from the evaluation work one option has emerged.

• Selective Catalytic Reduction ( SCR )