Emissions scandal inquiry finds diesel cars exceed UK pollution limits out on the road

None of the 37 top-selling cars met the legal limits for nitrogen oxide, with some emitting up to 12 times the legal limit

Air pollution has been linked to increasing stillbirth rates (Peter Macdiarmid/Getty Images)

All cars tested in a Government inquiry set up after the Volkswagen diesel emissions scandal exceeded pollution limits when tested in real world conditions.

None of the 37 top-selling cars met the current legal limits for nitrogen oxide when tested on the road, a Department for Transport (DfT) report found.

Some emitted up to 12 times more than the legal limit of 180 mg/km.

Cars meeting Euro 5 standards, which could be sold up to September last year, were all "substantially higher" in real world conditions than the measurements recorded in the laboratory.

The Vauxhall Insignia was the worst performer, emitting over 1,800 mg/km.

Even the Citroen C4, the best performer, was found to emit around three times the legal laboratory level.

Of the 19 new models tested which meet the current Euro 6 standards of 80 mg/km in laboratory tests, none could replicate the results on the road.

The report also found results varied depending on outside temperatures, with engines producing more emissions when it was cold.

Real world driving tests are to be introduced next year, although diesel cars will initially be allowed to pollute more than double the current legal level, because of their limited ability to reduce real world emissions in the short term.

After initially denying responsibility, Volkswagen admitted that the emissions figures for selected models had been deliberately fiddled

The £1 million investigation found no evidence of car manufacturers other than the Volkswagen Group fitting devices to cheat emissions tests.

VW admitted last September that 482,000 of its diesel vehicles in the US were fitted with software to switch engines to a cleaner mode when they were being tested for emissions.

VW admitted last September that 482,000 of its diesel vehicles in the US were fitted with software to switch engines to a cleaner mode when they were being tested (Getty Images)

Transport Secretary Patrick McLoughlin said: "Our tests published today have not detected evidence of manipulation of emissions lab tests as used by the VW Group by any other car manufacturer."

He went on: "The UK has been leading in Europe in pushing for real-world emissions tests which will address this problem.

"Real-world tests will be introduced next year to reduce harmful emissions, improve air quality and give consumers confidence in the performance of their cars.

"Following the Volkswagen emissions scandal, the whole of the automotive industry must work hard to restore public trust by being transparent about the systems they employ and advancing plans for introducing cleaner engine technology."

Oliver Hayes, a spokesman for Friends of the Earth, said: “This confirms what experts have been saying for years: deadly emissions are far higher in the real world than in controlled tests in the lab."

He added: “40,000 Britons a year are dying early due to air pollution. Under current plans a child born in London today could spend the first nine years of their life breathing illegally toxic air.

“What will it take for legislators to show courage and ban deadly diesel from the most polluted places. And introduce a generous diesel scrappage scheme to encourage motorists to switch.”

Additional reporting by PA