Photographer: Patrick Pleul/AFP via Getty Images

U.K. Cars on Average Six Times More Polluting Than Permitted

  • Investigators found no evidence of VW-Style defeat devices
  • New tighter rules to enter force in 2017 and then 2020

Diesel cars on U.K. roads on average emit more than six times the levels of air pollutants permitted in laboratory tests when driven in real-life conditions, the Department for Transport said.

U.K. tests on 37 different models uncovered no evidence of devices to defeat pollution tests in cars other than those made by Volkswagen AG, according to a report published on Thursday. At the same time, all the cars tested exceeded laboratory limits for dangerous emissions of nitrogen oxide when facing real-life conditions.

"Our tests published today have not detected any evidence of manipulation of emissions lab tests, as used by the VW Group, by any other car manufacturer," Transport Secretary Patrick McLoughlin said in a statement. "These tests do show the widespread use of engine management systems to prevent engine damage which can lead to higher emissions in real world temperature conditions than those in the approved lab tests."

While transport officials have for years known that cars pollute more when driven on roads than in laboratory conditions, Thursday’s probe shows the scale of the gap, underscoring the challenge faced by policymakers in trying to clean up dangerous levels of air pollution. The quality of London’s air has become an electoral issue in the capital’s May 5 mayoral vote, with all candidates promising to crack down on pollutants.

Not Alone

London isn’t alone: cities including Manchester, Liverpool and Glasgow are all in breach of European air pollution regulations on nitrogen oxide levels that came into force in 2010. The government predicts London won’t comply with the rules until 2025, and the Royal College of Physicians in February said about 40,000 people die a year because of exposure to air pollution.

Thursday’s study covered 18 so-called Euro-5 standard vehicle models, which were sold before September 2015, and 19 Euro-6 models sold since then. The probe, carried out alongside a wider investigation into 56 models by the German transport ministry, sought to uncover the real-conditions emissions of nitrogen oxide, as opposed to output of the pollutants under artificial test conditions.

Investigators found that vehicles in both categories emitted on average more than 6 times the amount of nitrogen oxide permitted under EU rules.

Worst Performer

The Vauxhall Insignia was the worst-performing Euro-5 model, emitting more than 1,800 milligrams of NOx per kilometer, compared to the 180 mg limit. The Citroën C4 was the best-performing at about three times the limit. The Peugeot 3008 was the worst-performing Euro-6 model with emissions of about 1,100 mg per kilometer, compared to the 80 mg standard. The Mini Countryman was the best-performing at just over 100 mg, the report said.

Other models investigated include cars made by Ford, Honda, Hyundai, Nissan, BMW and Toyota. The results for different models aren’t directly comparable because the exact road conditions varied from test to test, according to the report.

New models sold from next year will have to have real-world emissions of below 2.1 times the lab-testing limit from next year. From 2020, they’ll need to be at or below the laboratory standard, the department said.

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