emissions testing

New emission tests fail to determine diesel impact on air pollution

Despite the implementation of new emissions tests in the wake of the VW ‘cheat device’ scandal, new research has found that they do not capture the true impact that diesel vehicles have on air pollution.

Greenpeace commissioned independent testing of two popular diesel cars which found that emissions of harmful nitrogen pollutants (NOx) were significantly higher than those recorded in official tests.

A tougher testing regime for newly launched cars came into force on 1 September, requiring new models to undergo a more robust laboratory examination as well as tests while being driven on open roads with equipment attached to exhaust pipes.

But Greenpeace is concerned that regulations for the real-world tests are not stringent enough after Emissions Analytics tested a VW Golf and a Vauxhall Insignia on commuter routes in and out of London during the morning and evening rush hours.

It claimed NOx emissions on the most congested roads were up to 118 per cent higher for the Golf and 42 per cent higher for the Insignia than levels detected in official tests.

Greenpeace clean-air campaigner Paul Morozzo said: “The RDE [real driving emissions] tests should leave the auto industry no room to hide their cars’ real emissions but our investigation suggests this is not the case.

“These new tests are not ‘real’ enough to ensure the most polluting cars are kept off our roads. That car companies are allowed to avoid rush hour traffic when testing in urban areas is a major flaw.

“Instead of wasting more time and money hiding behind tests that still don’t reflect what’s happening in the real world, car companies should switch from diesel to electric and hybrid technology.

“Ministers cannot rest on their laurels either - these tests do not solve the problem of air pollution, which makes a ban on new diesels long before 2040 even more crucial.”

The new official tests are part of European regulations designed to improve air quality and tackle climate change by giving more accurate measurements.

The real-world driving requirement is designed to stop manufacturers cheating emissions tests.

Volkswagen Group fitted software to diesel models which manipulated examinations by detecting when the vehicles were on a rolling road.

The manufacturer said 11 million of its vehicles were affected worldwide, including almost 1.2 million in the UK.

A government testing programme last year found that modern diesel cars emit six times more nitrogen oxide in the real world than in the lab.

Under the new rules, manufacturers will have to slash those emissions by two-thirds but they will still be allowed at a higher level than acceptable laboratory limits.

For older cars, other fixes are being implemented to improve their performance. Five million diesel cars in Germany are currently awaiting software updates that will reduce their NOx emissions while nearly half a million in the US will get both hardware and software updates.

A further reduction in emissions will be required from September 2020.

Air pollution causes an estimated 40,000 premature deaths a year in the UK and is linked to health problems from childhood illnesses to heart disease and even dementia.

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