Volkswagen has adjusted carbon dioxide emissions ratings for many of its cars following on from the emissions scandal, but one leading academic has defended the move saying it’s a “normal process for car companies to refine CO2 numbers” .
Models such as the Polo, Golf, Passat and Touareg are included in the changes, which come in the wake of the the recent record settlement of $14.7 billion (£12 billion) in the USA for vehicles affected by the 2015 emissions scandal.
A company spokesman said: “In the interests of providing our customers with stated fuel consumption figures that are even closer to real-world driving, Volkswagen has voluntarily made slight adjustments within internal parameters for the NEDC homologation test. As a result of this, minor modifications have been made to the brochure data for some model variants going forwards.
“These changes have no impact on customers’ actual real-world consumption figures.”
The biggest alteration noted by Autocar’s data experts is the Golf 1.6 TDI with manual gearbox. It’s been updated from 99g/km to 103g/km. A Polo 1.0 MPI 60’s CO2 emissions are now rated at 108g/km where they were previously 106g/km.
Dr Jo Barnes, senior research fellow in air quality management at the University of the West of England, said: “It’s a normal process for car companies to refine CO2 numbers. It doesn’t mean there has been any impropriety at this stage VW is erring on the side of caution with these new figures.”
Dr Barnes added: “EU regulations have grey areas that have been exploited in the past. Now, car makers are keen to be seen to acting in the spirit of the law rather than just the letter of the law. However, there is still a significant gap between laboratory test results and real-world CO2 emissions.”
Other VW models which have CO2 emission tweaks include the Beetle, Jetta, Sharan and Touran. With both petrol and diesel engines having their emissions figures updated, some models registered a decrease in CO2 output, including all Tiguan S models and the Touran 2.0 TDI 150 DSG.
Volkswagen recently scored the highest A-rating in the EQUA Air Quality Index with the new Tiguan, making it the only diesel-engined car to achieve this top score. It’s also the fifth VW model to be rated with an A.