All new cars sold must meet Euro 6 standards for exhaust emissions of NOx and other pollutants
Environmental pollution, and the vehicle emissions that contribute to it, has had a major impact on the world we live in. Back in the day, car makers would produce cars that delivered bigger and better performance without regard for the pollutants coming out of the exhaust. However, as atmospheric studies have revealed a rise in pollutants in the air, governments and legislative bodies across the globe have clamped down on vehicle emissions to help reduce it.
Some will argue that vehicle pollution is just a slim percentage of overall emissions levels, but as the car industry is an easy one to regulate against, regional vehicle production standards have been adapted to improve the emissions of all vehicles. This has seen a shift in car manufacturing philosophies, as makers try to balance performance with emissions and a subsequent benefit in economy, while some makers have tried to tailor their cars to suit the test without any real-world emissions benefits.
But who sets the standards for car manufacturers to meet? And what is actually required to meet the latest emissions legislation? This guide rounds up the latest standards and testing procedures, and we also explain what new legislation is scheduled to come into place to improve emissions testing regulation and help avoid car makers short-cutting the tests.
Every new model that is sold in the UK has to undergo the New European Driving Cycle (NEDC) procedure before it can be sold in showrooms. This test measures emissions of each engine and gearbox combination a new car is sold with under laboratory conditions on a rolling road.
The procedure is conducted in a controlled environment, and tests are witnessed by Government agencies. The ambient temperature, vehicle fluid levels and tyre pressures are all measured to maintain consistency between tests of different models, and this ensures the test is as accurate as possible. That means all cars are tested in the same conditions and means that the emissions figures recorded for them can be compared directly to each other when you're comparing specs between cars.
The cars that are chosen for the test are randomly selected from the production lines by the legislative body. That means the manufacturer can't supply a specially 'tweaked' model that could be optimised to produce favourable results.
However, as Volkswagen proved, car makers can still bypass these regulations without doctoring a test model. To make emissions tests more reflective of real-world driving, a new testing procedure is currently under development which will be developed in 2017-2018 and will be the new industry standard in 2019.
The new plans are designed to more closely reflect fuel economy and emissions when actually driving, and include an additional real-world driving emissions (RDE) test to detect regulated pollutant emissions.
The RDE is to be carried out on the road instead of the lab, and will use a portable emissions measurement system to record emissions. The RDE element is expected to introduce a more realistic and stringent approach to emissions testing in the future, although of course atmospheric conditions will affect the results of this test.
Euro 6 is the sixth incarnation of the European Union directive to reduce harmful pollutants from vehicle exhausts. The Euro 6 standard was introduced in September 2015, and all mass-produced cars sold from this date need to meet these emissions requirements. The aim of Euro 6 is to reduce levels of harmful car and van exhaust emissions, both in petrol and diesel cars.
This includes nitrogen oxide (NOx), carbon monoxide (CO), hydrocarbons (THC and NMHC) and particulate matter (PM), which is basically soot from diesel cars. The knock-on effect of reducing these pollutants can also mean improved fuel economy and lower CO2 emissions. NOx is a harmful pollutant that is often blamed for damaging the environment, but has also been proven to have serious health implications. Particulate matter, meanwhile, is a local pollutant that has also been linked to health and respiratory problems.
The latest Euro 6 regulations set different emissions standards for petrol and diesel cars, but that is a reflection of the different kind of pollutants the two fuels produce. For diesels, the permitted level of NOx emitted has dramatically dropped to a maximum of 80mg/km, compared to the 180mg/km level that was required for cars that met the previous Euro 5 emissions standard. In contrast, the NOx limit for petrol cars remained unchanged from Euro 5, as it was already low at 60mg/km.
Diesel cars and the Euro 6 emissions standards Older diesel cars that produce higher levels of NOx and particulate matter are starting to come under fire from a number of environmental groups. Some have blamed the UK Government for enticing consumers into diesel cars, which are considered to be more environmentally harmful, with road tax and company car tax structures that benefit low CO2 emissions.
Diesel cars tend to be better than petrol models when it comes to CO2 output. The road tax argument is now null, because the Government introduced a new road tax structure in 2017, while the automotive industry and the Society of Motor Manufacturers and Traders (SMMT) that represents it have recently come out in defence of diesel cars and started a campaign to raise awareness of the clean diesel technology fitted to Euro 6-compliant models.
2nd of January 2019