News story

Tough new 'real world' test comes into force for diesel cars to clean up our air

New test for harmful emissions from car exhausts.

Car exhaust pipe.
  • new 90-minute test will recreate real life mix of urban, countryside and motorway driving
  • reforms will slash harmful nitrogen dioxide emissions by two-thirds for diesel cars
  • designed to stop car manufacturers cheating on the emissions test following Volkswagen emissions scandal

New models of diesel and petrol cars will have to pass a strict new emissions test before they are allowed on Britain’s roads from next week (1 September 2017).

The tough standards come into force in the biggest overhaul of emissions rules in a generation.

Under the old test, vehicles were tested in the lab on a rolling road but now they will have a 90-minute real world driving test. The limits are being introduced under European-wide reforms that the British government has led the way in calling for.

The nitrogen oxide emissions requirements for all new car models will be stricter again from 1 September 2020.

Transport Minister Paul Maynard said:

We are taking strong action to clean up our air and these tough new emissions standards will reduce dangerous pollutants.

This government has led the way in Europe pushing for on-road emissions tests, alongside a tough new laboratory test, to clean up air in our towns and cities.

This will ensure all vehicles meet rigorous standards when driven on our roads – and we are going even further tightening requirements again in 2020.

The government’s diesel testing programme last year found that today’s Euro 6 diesel cars were emitting 6 times more nitrogen dioxide in the real world than in the lab. Under the reforms, now they will have to slash those emissions by two thirds – helping clean up air in towns and cities across Britain.

The new test is also designed to stop car manufacturers cheating on the emissions test. Volkswagen manipulated test results with sensors that detected when the vehicle was running on a rolling-road in the lab.

During the 90-minute test vehicles will have emissions testing equipment attached to the exhaust pipe, and they must pass before they are approved to go on sale in Britain. The vehicle will have to do roughly equal splits of town, countryside and motorway driving. The test will then be rolled out for all new cars on sale in Britain from 1 September 2019.

The department has also recently set up a Market Surveillance Unit, which tests vehicles already on the road to make sure they meet emissions standards.

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Published 27 August 2017