Euro emission standards have evolved over the years, and as of 2024, they do not yet include non-exhaust emissions – including particulates from brakes and tyres. However, this will be considered for all new cars when the new Euro 7 emissions rules come into force.

Euro 6 is currently the latest exhaust emissions standard for new cars and it is a minimum requirement for diesel vehicles in a number of clean air zones, including the London ULEZ. Introduced in 2014, Euro 6 has four different versions. The latest update of this regulation – Euro 6d - was made a requirement for emissions standards in January 2021.

Read on for our Euro emissions checker and to find out if your vehicle will be affected by the European emissions standards. 

Euro emissions are a set of standards that intend on limiting the amount of CO2 emitted by cars. 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. Within the UK, transport contributes to 28% of total CO2 emissions – the standards aim is to reduce this.

Although emissions regulations date back to 1970, the first EU-wide standard – known as Euro 1 – wasn’t introduced until 1992, which saw catalytic converters become compulsory on new cars, effectively standardising fuel injection. 

Since then, there have been a series of Euro emissions standards, leading to the current Euro 6, introduced in September 2014 for new type approvals and rolled out for the majority of vehicle sales and registrations in September 2015.

Additionally, the EU has said that “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.”

In 2017, the SMMT 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, produces 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…because emissions in ‘real-world’ driving conditions are often higher than those measured during the approval test (in particular for diesel vehicles)”.

According to Department for Business, Energy & Industrial Strategy (BEIS) stats from 2018, transport still accounted for 33% of all carbon dioxide emissions, with most of this coming from road transport. 

However, BEIS estimates current emissions from road transport have fallen back by around 8.5% over the last decade to levels last seen in 1990, having previously peaked in 2007.

You can find your vehicle’s engine Euro emission rating on your V5C logbook. This important document will tell you what the official Euro emission rating of your car or van is. It is sometimes listed on the bottom of page two of the document, titled ‘Exhaust Emissions’.

You can also check your vehicle's emission rating with the Government’s clean air zone checker, Enter your vehicle’s registration and this free tool will tell you if there will be a daily charge to drive your vehicle in a specific Clean Air Zone. 

You can also check your car's Euro emission rating with the table below. It is reproduced from the standards set out by the European Commission and acts as a guide to show how the different Euro emissions categories are applied to new vehicle models approved after a specific date. 

Every car sold up to a year after the dates below should conform to the appropriate standards, but check with your manufacturer directly as some cars bought after the implementation date may still have the previous Euro standard. 

If your vehicle is older than any dates listed below, it won't have a Euro emissions standard, meaning you may be banned entirely from entering some towns and cities at certain times.

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For UK drivers, the standards are vital to the government’s strategy – called the Road to Zero – to support the transition to zero emission road transport, which includes a ban on the sale of new petrol and diesel cars by 2035 and a complete ban by 2050.

As part of this, many authorities across the UK have implemented or are considering implementing low-emission zones, following the example of London, which increased emissions restrictions by establishing the Ultra-Low Emission Zone (ULEZ) in April 2019.

Cities, such as Birmingham, Oxford, Bristol, Bath, Glasgow, Edinburgh, Manchester and Newcastle all have similar low emissions zones. Some of them are aimed at commercial vehicles rather than private cars, though, for the time being. 

The clean air zones have also kickstarted the electric car revolution, where an increased number of drivers are making the switch to an EV. 

London’s ULEZ restricts vehicles based on their Euro emissions standards, with those that do not meet the standard required to pay a toll.

The minimum emissions standards are Euro 4 for petrol vehicles and Euro 6 for diesels. The daily ULEZ charge is £12.50.

Where previously London's ULEZ only incorporated the city centre, as of August 2023 the Ultra Low Emission Zone now covers all of London's boroughs and almost all of Greater London. 

For more information on what ULEZ charges your vehicle will face, see Transport for London’s guide.

• The Expanded Ultra-Low Emissions Zone: What you need to know
• Clean Air Zones – what are they and where are they?
• Crit'Air clean air stickers - need to know for driving in France

Knowing your car’s emissions standard is even more important if you’re planning on driving across Europe. Several cities and regions across Europe have low-emission zones, and these zones use Euro standards to regulate them.

In France, these regulations are called the Crit’Air system, a multi-category system that sees vehicles defined by their emissions through a coloured, numbered sticker on their windscreen. 

Cities, including Paris, have a permanent low-emission zone in place which restricts entry of the most polluting vehicles during certain times through the week.

Other areas have emergency zones in place, which see temporary restrictions introduced when air pollution is dangerously high. Entry is then based on the Crit’Air number displayed on each vehicle. 

For more information, read our guide to Crit’Air stickers.

A new standard for exhaust emissions is on the way, having been voted on by European Parliament. Known as Euro 7, it incorporates a whole new set of regulations including ones for electric vehicles (EVs).

What are the main features of Euro 7?

• Non-exhaust emissions: Euro standards will aim to address non-exhaust emissions for the first time, for example by reducing brake dust and tyre particle pollution
• More real-world testing: Vehicles tested under Euro 7 standards will be tested in a variety of temperatures and on short journeys
• Extended compliance: Cars and vans will be required to meet these standards for 10 years and 124,000 miles (200,000 km)
• EV battery testing: Electric vehicles and plug-in hybrids will have their batteries tested for longevity and performance

These rules were originally planned to be even stricter, but debates over feasibility and the pressure it puts carmakers under have watered down some of the targets in specific exhaust emission reduction.

When does Euro 7 come into effect?

Euro 7 is due to come into force in November 2026. 

In order for cars to be classed as Euro 6 compliant, diesels should emit no more than 0.08g/km of NOx while petrols should not exceed 0.06g/km.

To meet Euro 6 standards, 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.

Implementation date (new approvals): 1 September 2014

Implementation date (most new registrations - see important point below table above): 1 September 2015

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

The standards were updated to include newer versions of vehicles impacted by the levels of emissions.

On 1 January 2020, the European Commission announced that Regulation (EU) 2019/631 entered into force, setting CO2 emission performance standards for new passenger cars and vans. It replaced and repealed the former Regulations for cars and vans individually. As the new target started applying in 2020, the average CO2 emissions from new passenger cars registered in Europe have decreased by 12%.

There was then a further development a year in July 2021, where new proposals were introduced to help the EU reach its climate neutrality goals by 2050 – and a net reduction of greenhouse gas emissions by 2030.

Euro 6d-Temp, Euro 6d and Real Driving Emissions (RDE)

Since 2017, more realistic tests have been introduced to ensure new cars meet the latest emission limits.

The Worldwide Harmonised Light Vehicle Test Procedure (WLTP) was introduced in 2017 to measure fuel economy and emissions. WLTP is designed to more closely reflect real-world driving performance and provide a more realistic understanding of how much fuel a car will use and how much tailpipe pollution it produces.

While emission limits for Euro 6 has remained unchanged, the method for measuring performance has been updated over the years. Euro 6c represents vehicles tested under WLTP standards, while Euro 6d-TEMP and Euro6d represents cars that have been tested against RDE (Real Driving Emissions). 

The RDE test operates alongside the WLTP laboratory standard and is designed to ensure that all new cars meet their emission limits in a range of real world driving conditions. 

For a diesel car to meet Euro 5 it must have a diesel particulate filters (DPF) and emit no more than  0.18g/km of NOx gases, while a petrol car can emit no more than 0.06g/km.

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.

In the context of the Ultra Low Emission Zone (ULEZ) in London, some Euro 5 vehicles can enter without having to pay a daily fee. This is because Euro 5 vehicles are considered to be relatively low emitters and therefore compliant with the ULEZ standards. However, Euro 5 vehicles that do not meet the Euro 6 standards for nitrogen oxides (NOx) will be subject to a daily charge.

Implementation date (new approvals): 1 September 2009

Implementation date (all new registrations): 1 January 2011

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

For a diesel car to meet Euro 4 it must emit no more than  0.25g/km of NOx gases, while a petrol car can emit no more than 0.08g/km.

Euro 4 was introduced in 2005 and applied to all new cars sold from January 2006.

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 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.

Implementation date (new approvals): 1 January 2000

Implementation date (all new registrations): 1 January 2001 

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 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.

Implementation date (new approvals): 1 January 1996

Implementation date (all new registrations): 1 January 1997 

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

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.

Implementation date (new approvals): 1 July 1992

Implementation date (all new registrations): 31 December 1992 

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

While Euro standards have ensured a reduction in vehicle emissions, the so-called ‘dieselgate’ scandal highlighted that there’s still work to be done, not least because carmakers felt the need to ‘cheat’ to meet the stringent standards.

In 2017, the EU introduced a ‘Real Driving Emissions’ (RDE) test. It’s hoped this will better reflect actual emissions on the road, reducing the discrepancy between real-world emissions and those measured in a laboratory.

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In the words of the Government: “You cannot get an MOT certificate if your vehicle’s exhaust emissions are too high.”

Following the introduction of new rules in May 2018, the MOT test now includes stricter requirements surrounding emissions. 

Any car that has been fitted with a diesel particulate filter (DPF) (a requirement for all Euro 5 and 6 diesels) that gives out "visible smoke of any colour" during testing will get a major fault – an automatic fail.

It will also fail if the MOT tester finds evidence that the DPF has been tampered with. Read more on the new MOT rules. 

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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 Euro 5 emission standards apply to the sale of two and three-wheeled vehicles – following an update from the Commission in 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