Researchers claim at least four more car manufacturers could be embroiled in emissions scandal
Researchers at the Institute for Transport Studies at Leeds University have claimed four more major car manufacturers could be dragged into the Volkswagen emissions scandal.
Following tests on hundreds of new diesel cars British researchers found that brands including BMW, Ford, Mazda and Mercedes, as well as Volkswagen and Audi, emitted far higher levels of nitrogen oxides (NOx) than the limits required to pass European tests.
"The surprising finding for us was that even the Volkswagen engines were polluting 35 per cent less than comparable cars, suggesting all manufacturers have found their own ways of passing the laboratory tests," said Dr James Tate, lecturer and researcher at the Institute for Transport Studies at Leeds University.
"We found small city diesel cars are emitting more than double-decker buses or fully laden 40-tonne articulated lorries. This is big business for them [car manufacturers]. It lets them sell tax-friendly, powerful luxury cars with supposedly low emissions levels and make higher profits."
Dr Tate's research has been monitoring diesel emissions on Britain's roads for five years, recording over one million cars. His latest research focused on Euro Six category diesel engines, measuring 300 diesel cars in six locations across England and Scotland.
Recorded over six days this summer the finding show, on average, none of the manufacturers met the Euro Six regulations with Ford's new diesel engines emitting more NOx on average than the other brands tested.
Euro Six regulations state engines must not produce more than 0.08g of NOx per kilometre, Volkswagen's offending vehicles were found to be releasing 4.2x the limit but some of those tested by Dr Tate were found to be emitting 5.8x the regulated amount.
Dr Tate added the research showed manufacturers were building cars purely to perform well in lab tests, without concern for the amounts of NOx released in the real world.
"Very little is known about how the manufacturers conduct their tests," said Dr Tate. "What our tests do for the first time is show how much toxic fumes are really being emitted in British roads, and we have done that with a large sample size to give a much more accurate picture of the true scale of the problem."
Greg Archer, of pressure group Transport and Environment, said the results show Volkswagen's problems are "the tip of the iceberg" with Dr Tate calling for cars to now be tested in 'real-world' conditions.