A guide to Euro 6 car emissions

In a world that is increasingly eco-aware, car emissions are a hot topic. Measures are being put in place across the UK and the automotive industry to increase the amount that is charged to drivers of high emission cars.

Low-emission zones are being set up in cities and, in general, car manufacturers are moving towards eco-friendly engines and fuel types. This change in focus by manufacturers is also being met with increased demand from consumers for electric cars, with sales of electric cars and hybrids increasing between 2014 and 2019.

Euro 6 is the name given to the set of limits on hazardous or damaging gases and particles emitted by cars. Each car manufacturer is required to meet Euro 6 standards when producing new models. These standards are also used in the framework for cars that are permitted in low-emission zones.


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What are the Euro 6 emissions standards?


Euro 6 emissions standards are designed to bring clarity to the amount of emissions each vehicle on the road contributes.

The standards differ for petrol and diesel cars, but both are focused on nitrous oxides and hydrocarbons. For petrol cars, the standard says that emissions above 60mg/km are noncompliant, though the number is higher for diesels at 80mg/km.

If your vehicle is noncompliant and you drive in some city centres with congestion charges, you could be liable to pay up to £12.50 per day to improve air quality. As more stringent measures come into place to help reduce emissions, it is likely that even more incentives could be released to encourage drivers to switch to Euro 6 cars.

The full current standards are as follows:

Petrol Diesel
CO 1.0g/km £0.50g/km
THC 0.10g/km -
HC + NOx - 0.17g/km
NMHC 0.068g/km -
PM 0.005g/km (direct injection only) 0.005g/km
PN [#/km] 6.0x10^11/km (direct injection only) 6.0x10^11/km

How are Euro 6 tests carried out?


Historically, Euro 6 tests were carried out on a rolling road inside a laboratory or test centre. However, it was discovered that these artificial tests could be manipulated which has resulted in them moving outside. Now, cars are required to pass a road test to monitor emissions. This test is called a Real Driving Emissions test (RDE).

As a result of this testing, the Euro 6 limits were increased to account for lower fuel economy in outdoor situations.

From January 2022, new cars will have to pass the RDE test but there will be lower limits in place in a new version of the test named RDE2, making it more equivalent to the levels that were originally set for the indoor tests. The new standard measured for in the RDE2 tests will be called Euro 6d.


Is my car Euro 6 compliant?


Any cars registered after September 2015, when Euro 6 became mandatory, will be Euro 6 compliant as standard.

Many cars manufactured before that date will also be compliant with Euro 6 regulations but older models may only be Euro 5 compliant.

You can check if your car is Euro 6 compliant by comparing your car’s emissions with the Euro 6 standards in the table above, or by using a Euro 6 checker online.


Benefits of a Euro 6 car


The benefits of having a Euro 6 car are clear. Owners pay lower tax rates, lower company car tax, and zero fees when driving in Low Emissions Zones – all whilst knowing that they are doing the best they can do ensure their emissions are at the current approved rate.

Euro 6 standards also ensure that engine manufacturers are forced to make engines as efficient as possible in terms of fuel consumption, resulting in forward-thinking design that helps the planet.


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