The European Commission decided to issue a reasoned opinion on Thursday to Austria, Belgium, Cyprus, the Czech Republic, Finland, Greece, Latvia, Romania, Spain, and the United Kingdom for failing to transpose EU rules on quality of petrol and diesel fuels (Council Directive (EU) 2015/652) into their national law. The Directive lays down rules to calculate and report the greenhouse gas emissions of fuels and other energy from non-biological sources. The EU regulation aims to yield reporting of sufficient accuracy, so that the Commission can assess the performance of fuel suppliers in meeting their obligations under the Fuel Quality Directive (Directive 98/70/EC). The Fuel Quality Directive aims to achieve at least a 6% reduction of the greenhouse gas intensity of the fuel and energy supplied by the end of 2020. The calculation method has also the advantage of reducing the administrative burden on both suppliers and Member States. Member States had to implement EU rules on the calculation and reporting of greenhouse gas emissions of fuels into their national legislation by 21 April 2017. The Commission had already sent a letter of formal notice to these Member States in May 2017. If the concerned Member States fail to act within two months from the receipt of the reasoned opinion, the case may be referred to the Court of Justice of the EU.