Some new diesel engines found to emit 11 times more pollution than legal limit

New research has revealed that some diesel cars on British roads are even more polluting than initially suspected.

A study by the FIA Foundation and the International Council on Clean Transport tested a variety of vehicles and found that those produced by the Renault-Nissan-Mitsubishi alliance were the worst performers, emitting on average 11 times the legal limit of 0.08g/km of nitrogen oxides.

Diesel vehicles from the Fiat Chrysler Alliance and Hyundai Motor Group weren’t too far behind. The report comes from the same companies that unearthed the Volkswagen emissions scandal, and involved measuring the actual tailpipe emissions of 100,000 vehicles at nine locations in London.

The emissions were measured by firing infrared and ultraviolet light through the car’s exhaust plumes, before recording the contents.

Perhaps surprisingly, the previously disgraced Volkswagen Group performed second-best – with only Jaguar Land Rover proving cleaner. However, even JLR still emitted more than double the legal limit of nitrogen oxides – with the average manufacturer emitting six times more than allowed.

The research also found that London has a serious problem with black cabs – with the study finding them to be some of the capital’s most polluting vehicles. In fact, the most common black cab models in London are producing NOx emissions of up to thirty times that of personal cars.

It also highlighted the necessity of the Euro emissions standards – cars of Euro 5 and older emit around 60 per cent of greater London’s nitrogen oxide emissions from passenger cars.