From laboratory to road: A 2014 update of official and “real-world” fuel consumption and CO2 values for passenger cars in Europe

This study, which builds on and extends the analysis begun in 2012 and continued in 2013, demonstrates that the year-over-year improvements reported via the type-approval tests are not reliably matched in everyday driving—and that the gap between the vehicle emissions testing laboratory and the real world of the road is getting wider. [...] The data reveals a rapid increase in the models’ divergence between 2011 and 2013, about at the same time as the introduction of the 208 in 2012. [...] This upswing occurred after the seventh genera- tion of the Passat was introduced in 2010.10 In contrast to the Passat, the Golf and Polo exhibit a more gradual increase in these years; however, the divergence of the Golf increased steeply last year. [...] The aggregation of individual vehicle data to fleet-wide averages was based on the LeasePlan vehicle count; in other words, the aggregated data is representative of the LeasePlan fleet but does not reflect the composition of the German market. [...] The amount of fuel added after the test is the basis for the calculation of the car’s fuel consumption.