Nowadays all new cars sold in European markets, including Britain, are required to meet standards for exhaust emissions of NOx and other pollutants, (Euro emission standards.)
Over the years, different and more restrictive limits on what new cars are allowed to emit have come into play in order to make them cleaner. The issue of how many pollutants a car lets out is significant as it affects both safety and the running costs of vehicles.
In this guide, we summarise how the euro emission standards work and what they mean for new car buyers.
Euro 6 emission standards
Since September 2015 onwards, new cars sold in Britain and the rest of Europe have been required to meet Euro 6 emission standards.
This regulation covers how much of various pollutants are allowed to come out the exhaust pipe of a new car sold in Europe. The range of pollutants covered for both petrol and diesel models includes carbon dioxide (CO), hydrocarbons (HC), nitrogen oxide (NOx) and particulate matter (PM), the latter basically being soot.
NOx is a pollutant which EU regulators are particularly concerned about because it can potentially cause a lot of damage to both the environment and the health of members of the public.
This is more of an issue with diesel cars, even though they tend to record a lower CO2 output, leading to lower Vehicle Excise Duty costs. Therefore the emissions regulations set different standards for petrol and diesel cars, with the permitted level of NOx much lower for diesel models, especially since the introduction of Euro 6 rules.
How are car emission standards measured?
Each new car model in Britain and the rest of the EU are tested via the New European Driving Cycle (NEDC) procedure. Here the emissions output is worked out under laboratory conditions and using rolling roads.
Each test is held in a controlled environment where the temperature, fluid levels and tyre pressures are measured. Government agencies also act as witnesses to testing to ensure the procedure is followed correctly.
To make the emissions readout as accurate as possible to what owners will experience, the cars tested are randomly selected from production lines. This is preferable to, say, letting a manufacturer supply a car directly.
That’s because (theoretically at least) it should be a lot harder for the relevant manufacturer to manipulate the test results with software or any other tricks on the car scrutinised.
The effect of vehicle emission standards
Because manufacturers are informed of the latest Euro emission standards years in advance, they get plenty of time to get their latest models ready for the latest regulations before they come into force.
This from time to time can lead certain companies to drop a model because it will be unable to comply with upcoming emission regulations. More likely though, it will lead to a change of engines to make a particular car less pollutant in case it was set to miss the cut. New cars launched not long before new vehicle emissions standards come into force can easily ensure their engines are compliant before launch.
Really, the effects of car emission standards like the recent Euro 6 regulations could barely be noticeable to a lot car buyers in Britain. Although motorists who bought cars that followed previous EU regulations and then went on to buy a car that follows the latest rules are better placed to notice raised standard for fuel economy and cheaper Vehicle Excise Duty.
Future changes
More is planned to be done by the EU, however, to make their emissions tests better reflect real world driving. To achieve this, new testing procedures are currently under proposal with a view to being introduced in 2017.
The proposal includes an additional real word driving emissions (RDE) test, which will see cars assessed while driving out on the road rather than in a lab. While a car is moving on the road, a portable emissions measurement device will be used to record the emissions.
