Changes to Council Directive of 6 February 1970 on the approximation of the laws of the Member States relating to the type-approval of motor vehicles and their trailers (70/156/EEC)
EU Directive 1970/156
Made by Directive 2004/3/EC of the European Parliament and of the Council of 11 February 2004 amending Council Directives 70/156/EEC and 80/1268/EEC as regards the measurement of carbon dioxide emissions and fuel consumption of N1 vehicles
From legislation.gov.uk's record of changes, the official one: see it there.