The current Euro 6 emissions standard is the toughest standard yet and has the potential to eliminate the majority of exhaust pollutants that have an impact on air quality.

But what do these Euro emissions standards mean for you and what does the future hold for petrol and diesel engine cars?

What are the European emissions standards?

While emissions regulations date back to 1970, the first EU-wide standard – known as Euro 1 – was introduced in 1992.

Catalytic converters became compulsory on new cars sold in the UK as Europe wised up to the need to reduce tailpipe emissions. This effectively standardised fuel injection on new cars.

Since then, we have passed through a series of Euro emissions standards, leading to the current Euro 6, introduced in September 2014 for new type approvals and September 2015 for all vehicle sales and registrations.

The regulations – which are designed to become more stringent over time – define acceptable limits for exhaust emissions of new light duty vehicles sold in EU and EEA (European Economic Area) member states.

Why do we have them?

According to the EU, “The air pollutant emissions from transport are a significant contribution to the overall state of air quality in Europe”, with industry and power generation being the other major sources.

The aim of Euro emissions standards is to reduce the levels of harmful exhaust emissions, chiefly:

• Nitrogen oxides (NOx)
• Carbon monoxide (CO) 
• Hydrocarbons (HC)
• Particulate matter (PM)

These standards are having a positive effect, with the SMMT (Society of Motor Manufacturers and Traders), claiming: “It would take 50 new cars today to produce the same amount of pollutant emissions as one vehicle built in the 1970s.”

The SMMT has quoted the following figures in support:

• Carbon monoxide (CO): petrol down 63%, diesel down 82% since 1993
• Hydrocarbons (HC): petrol down 50% since 2001
• Nitrogen oxide (NOx): down 84% since 2001
• Particulate matter (PM): diesel down 96% since 1993

Because petrol and diesel engines produce different types of emissions they are subject to different standards.

Diesel, for example, produce more particulate matter – or soot – leading to the introduction of diesel particulate filters (DPFs).

The EU has pointed out, however, that NOx emissions from road transport “have not been reduced as much as expected. Since emissions in real-life driving conditions are often higher than those measured during the approval test (in particular for diesel vehicles)”.

As the UK government pointed out in December 2016, road transport still accounted for 34% of UK NOx emissions in 2015. The rate of reduction in atmospheric NOx has slowed down due to the increased contribution from diesel vehicles.

Over the same time, average new car CO2 emissions have more than halved, going some way to meeting the target average of 95g/km by 2020. CO2 emissions are linked to climate change and subject to different regulations.

Travelling to France?

Knowing your car's emissions standard is more important than ever now, as different cities around Europe are beginning to impose charges for higher emitting vehicles. These vehicles are identified when they enter specific cities by a colour-coded sticker which is based on your car's Euro emissions standard.

This system is currently active in some major cities in France, and if you are caught entering a city without one of the stickers - or drive a vehicle which is banned on a particular day - you could face a fine. To find out more on the recent law France change visit our clean air certificates page.

Importantly, if you drive a pre-1992 car that doesn't meet any Euro emissions standard (double check with your manufacturer if you're not sure), you're vehicle will not be permitted to enter those zones during times when restrictions are in place.

Don't get caught out abroad: make sure you have European Breakdown Cover.

How can I find out my car’s Euro emissions standard?

The table below, reproduced from that developed by the European Commission, shows the different Euro categories that apply to new vehicle models approved after a specific date. Every car sold up to a year after the dates below has to conform to the appropriate standards.

If your vehicle is older than any dates listed below (check with your manufacturer directly if you're not sure), it won't be classed as even a Euro 1 - meaning certain cities may charge or ban you from driving in them at certain times.

If you have a newer vehicle, you can also look up the emissions standard of your car and get a free vehicle valuation at the same time, courtesy of RAC Cars (your emission standard will appear at the end of the car description as part of the final step of your car valuation, indicated by the letters 'EU' in front of it).

Each Euro emission standard: a full breakdown

To find out what the different criteria cars have to hit to meet their Euro standard we have outlined each of the standards below. 

Euro 1 (EC93)

Implementation date (new approvals): 1 July 1992

Implementation date (all new registrations): 31 December 1992

The first Europe-wide euro emissions standards were introduced in July 1992 and the regulations weren’t anywhere near as stringent as they are today. That said, the fitment of catalytic converters became compulsory on all new cars, and Euro 1 required the switch to unleaded petrol.

Back then, only hydrocarbons and nitrogen oxide were tested, along with particulate matter in the case of diesel engines. Over the years, the regulations have become stricter and the limits lowered.

Euro 1 emissions standards (petrol)

CO: 2.72g/km

HC + NOx: 0.97g/km

Euro 1 emissions standards (diesel)

CO: 2.72g/km

HC + NOx: 0.97g/km

PM: 0.14g/km

Euro 2 (EC96)

Implementation date (new approvals): 1 January 1996

Implementation date (all new registrations): 1 January 1997

Euro 2 reduced the limits for carbon monoxide and the combined limit for unburned hydrocarbons and nitrogen oxide, as well as introducing different levels for petrol and diesel engines.

Euro 2 emissions standards (petrol)

CO: 2.2g/km

HC + NOx: 0.5g/km

Euro 2 emissions standards (diesel)

CO: 1.0g/km

HC + NOx: 0.7g/km

PM: 0.08g/km

Euro 3 (EC2000)

Implementation date (new approvals): 1 January 2000

Implementation date (all new registrations): 1 January 2001

Euro 3 split the hydrocarbons and nitrogen oxide limits for petrol and diesel engines, as well as adding a separate nitrogen oxide limit for diesel vehicles. The warm-up period was removed from the test procedure.

Euro 3 emissions standards (petrol)

CO: 2.3g/km

THC: 0.20g/km

NOx: 0.15g/km

Euro 3 emissions standards (diesel)

CO: 0.66g/km

HC + NOx: 0.56g/km

NOx: 0.50g/km

PM: 0.05g/km

Euro 4 (EC2005)

Implementation date (new approvals): 1 January 2005

Implementation date (all new registrations): 1 January 2006

Euro 4 emissions standards (petrol)

CO: 1.0g/km

THC: 0.10g/km

NOx: 0.08g/km

Euro 4 emissions standards (diesel)

CO: 0.50g/km

HC + NOx: 0.30g/km

NOx: 0.25g/km

PM: 0.025g/km

Euro 5

Implementation date (new approvals): 1 September 2009

Implementation date (all new registrations): 1 January 2011

The big news for Euro 5 was the introduction of particulate filters (DPFs) for diesel vehicles, along with lower limits across the board. For type approvals from September 2011 and new cars from January 2013, diesel vehicles were subject to a new limit on particulate numbers.

DPFs capture 99% of all particulate matter and are fitted to every new diesel car. Cars meeting Euro 5 standards emit the equivalent of one grain of sand per kilometre driven.

Euro 5 emissions standards (petrol)

CO: 1.0g/km

THC: 0.10g/km

NMHC: 0.068g/km

NOx: 0.06g/km

PM: 0.005g/km (direct injection only)

Euro 5 emissions standards (diesel)

CO: 0.50g/km

HC + NOx: 0.23g/km

NOx: 0.18g/km

PM: 0.005g/km

PN [#/km]: 6.0x10 ^11/km

Euro 6

Implementation date (new approvals): 1 September 2014

Implementation date (all new registrations): 1 September 2015

The sixth and current incarnation of the Euro emissions standard was introduced on all new registrations in September 2015. For diesels, the permitted level of NOx has been slashed from 0.18g/km in Euro 5 to 0.08g/km.

A focus on diesel NOx was the direct result of studies connecting these emissions with respiratory problems.

To meet the new targets, some carmakers have introduced Selective Catalytic Reduction (SCR), in which a liquid-reductant agent is injected through a catalyst into the exhaust of a diesel vehicle. A chemical reaction converts the nitrogen oxide into harmless water and nitrogen, which are expelled through the exhaust pipe.

The alternative method of meeting Euro 6 standards is Exhaust Gas Recirculation (EGR). A portion of the exhaust gas is mixed with intake air to lower the burning temperature. The vehicle’s ECU controls the EGR in accordance with the engine load or speed.

Euro 6 emissions standards (petrol)

CO: 1.0g/km

THC: 0.10g/km

NMHC: 0.068g/km

NOx: 0.06g/km

PM: 0.005g/km (direct injection only)

PN [#/km]: 6.0x10 ^11/km (direct injection only)

Euro 6 emissions standards (diesel)

CO: 0.50g/km

HC + NOx: 0.17g/km

NOx: 0.08g/km

PM: 0.005g/km

PN [#/km]: 6.0x10 ^11/km

MORE ADVICE: Petrol or diesel? Facts and quiz to help you choose

What next?

While vehicle emissions have reduced, the so-called ‘dieselgate’ scandalhighlighted that there’s still work to be done, not least because carmakers felt the need to ‘cheat’ to meet the stringent standards.

In light of the use of ‘defeat devices’, the EU is introducing a ‘Real Driving Emissions’ (RDE) test procedure, starting from 1 September 2017. It is hoped that this will better reflect the actual emissions on the road, reducing the discrepancy between real-world emissions and those measured in a laboratory.

Although the UK is negotiating its exit from the European Union, the emissions standards are expected to remain unchanged. One thing’s certain: cars are easy to regulate, so we can expect stricter euro emissions standards over the coming years.

Keep up to date with the latest air quality news

Motorbike Euro emission standards

The Euro emissions standards for motorbikes are slightly different from cars, with fewer new standards having been introduced over the years (due to motorbikes emitting less emissions than cars and other larger vehicles do).

Currently new motorbikes are regulated at a Euro 4 standard with Euro 5 due to be introduced in January 2020.

The implementation of emission standards for motorbikes is also a little more complicated than the standards for cars.

Motorbike emission regulations for Euro 1 to 3

Motorbike emission regulations for Euro 4 and 5