RENAULT diesel cars emit the highest levels of toxic nitrogen oxides of all the big manufacturers and the French company’s recent models produce nine times the legal limit, tests have found.
Volkswagen, which has paid £15bn to settle cases in the US over cheating emissions tests, now produces the least-polluting cars, according to Which?, the consumer group.
Jeep, Nissan, Hyundai and Ford scored badly in the Which? tests, producing at least five times the limit.
French fraud investigators have accused Renault of cheating tests for 25 years and said the “entire chain of management” was aware of the suspected fraud, according to a leaked official report.
NOx emissions were tested in 278 diesel cars made between 2012 and 2016. The Which? tests, like the official tests, were conducted on a rolling road in a laboratory but were closer to actual driving, with higher speeds and no tampering with the cars such as by over-inflating tyres or reducing weight.
“The method employed by Which? is very different from the current official EU test, so it’s no surprise it delivers different results”
It found that there was little reduction in NOx emissions in Renault models sold since 2015 compared with those sold in 2012. An emissions standard, known as Euro 6, was introduced in 2014 to halve the amount of NOx that a car could legally emit, from 0.18g/km under the previous limit to 0.08g/km.
Renault models sold from 2012 to 2014 produced an average of 0.73g/km, or four times the Euro 5 limit, and models from 2015 and 2016 produced 0.72g/km, nine times the Euro 6 limit.
The 33 BMW and BMW-owned Mini cars Which? tested had some of the lowest emissions for diesels, though they still exceeded the limit. The averages for BMW were 0.41g/km for Euro 5 cars and 0.14g/km for Euro 6 cars.
Two Mini models were the only ones to achieve the legal limit in the Which? tests. Two Jeep models produced at least nine-and-a-half times the Euro 5 limit, the worst results overall. The worst of these was the Jeep Grand Cherokee, registered from 2011 onwards, which produced 15 times the NOx legal limit.
Richard Headland, editor of Which? magazine, said: “While our tests show that some car manufacturers are making progress on reducing the amount of toxic emissions from their models, many have a long way to go.
“We hope that the improved official tests being brought in later this year will more clearly name and shame those manufacturers that are failing to meet their obligation to lower emissions.”
Renault said: “All Renault vehicles conform to the current standards. Since mid-2015, Groupe Renault has committed to improve the performance of its anti-pollution systems. The vehicles tested by Which? would not have benefited from this improvement plan.”
Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders, said: “Testing by government has consistently shown that vehicles meet the legal emissions limits. However, the method employed by Which? is very different from the current official EU test, so it’s no surprise it delivers different results.
“Industry is investing billions reducing emissions of all types and a new, tougher official lab test and on-road testing coming later this year will mean Europe has the world’s strictest emissions testing regime.”
Ben Webster, Environment Editor
This article first appeared in The Times