It emerged that the exaggerated fuel efficiency resulted from errors in testing procedures. The precise nature of the errors is not known, but affected the so called ‘coastdown test’ that measure how aerodynamic the vehicle is and its rolling resistance.
In Europe and the USA, vehicles are tested by licensed agencies. The ICCT says the exaggerated fuel economy would not have slipped through if the US Environmental Protection Agency had monitored whether the tests were being carried out properly. The EPA used to monitor a sample of tests every year, but stopped this because it had found no violations of testing rules. The ICCT says enforcement of all rules relating to all aspects of vehicle performance should take place if testing is to reflect real-life driving conditions.
Campaigners in Europe have long been sceptical about discrepancies between type approval testing done in simulated conditions and real-life driving performance, especially to do with fuel consumption and pollutant emissions.
T&E’s Greg Archer said: ‘The system of compliance in the EU is far weaker than that in the US – yet problems still occurred in the US. The European Commission needs to look at the system of type approval and conformity of production to ensure tests are properly conducted and the vehicles sold achieve the same performance as those tested. A good start would be to establish an EU-wide Type Approval Authority to ensure rigour and consistency EU-wide.’