Average real-world emissions of Euro 6 cars are 39% over their legal limit, according to new data from Emissions Analytics.

The Citroen C3 diesel is the only car that achieves the A1 rating in the new EQUA CO2 Index

Launched as the latest part of the EQUA Index series, the CO2 figures show the extent to which actual emissions of greenhouse gases from cars exceed the official figures on which our national objectives and vehicle taxation are based.

The new EQUA CO2 Index rates cars for their absolute level of CO2 emissions, and how close to their official figures they get.  The ‘A1’ rating – where ‘A’ represents the best absolute emissions and ‘1’ the accuracy factor – is currently only achieved by one vehicle, the Citroen C3 diesel.

Taking the car market as a whole, average real-world emissions of Euro 6 cars are 181g/km of CO2 – the same as for the previous Euro 5 generation and up 39% on the current legal fleet average target of 130g/km.

The data also finds that the gap between average CO2 emissions from petrol and diesel is closing – average CO2 emissions from new petrol cars have fallen by 6% since 2012, when Emissions Analytics started collecting data while the figure for diesel cars has risen by 5%.

Nick Molden, CEO and founder of Emissions Analytics, said: “In recent years, we have been kidding ourselves about our actual achievement in reducing CO2 from cars. Encouraging official data has given a misleadingly positive impression. The new official world harmonised test will help close the gap, but only partially.”