Emissions Testing for New Cars

The toughest ever emission testing is now in force for every new car sold in the UK. Replacing a 20 year old single test, this new real world testing is going to provide a more accurate representation of the vehicles CO2 and fuel economy figures on the road.

Nitrogen Oxides (NOX), Carbon Monoxide (CO), Particulates by Mass and Particulates by Number (PM/PN) will also be a part of the new tests that form the new European regulations aimed at reducing climate change and improving air quality.

So from this month going forward every new car will undergo a Worldwide Harmonised Light Vehicle Test Procedure or WLTP that measures and monitors all regulated emissions from the modern day petrol or diesel engine.

Like the previous test, it’s conducted in a controlled laboratory for consistent conditions across every car tested in all countries. However the test will be dynamic, longer and the engine ran much faster, at a range of speeds, engine load, gear changes and temperatures.

In a world first, new models being developed for sale within the UK will have a second test based on real road driving. The cars will have portable emission test equipment installed and will then need to prove their Euro 6 credentials, by passing the pollutant tests while out on the public highways.

An illustration of a portable emissions test rig fixed on a car.

The outgoing test known as the New European Driving Cycle first came into play in the 1980’s and was updated in 1997. Over the past 20 years cars have developed significantly and some even have semi autonomous driving, all the new technology has resulted in a gap between lab testing and on the road real world emissions.

So the whole industry and regulators have come together with national governments to create new testing methods more relevant to modern vehicles and emissions standards.

The new WLTP emission test compared with the old NEDC

A diagram comparing the old emission testing with the new system.

Mike Hawes, Society of Motor Manufacturers and Traders’ chief executive, said: “Combined, these new and demanding tests will soon give consumers emissions performance information that is far closer to what they experience behind the wheel – and inspire greater confidence that the new cars they buy are not only the cleanest, but the most fuel efficient ever produced.”