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Understanding your car’s Euro standard

Understanding your car’s Euro standard

The London T-Charge is just the start. In the battle to improve urban air quality, we can expect to see more and more penalties for older, more polluting vehicles. 

The UK Government has already laid out its plans for a cleaner environment with its Air quality plan for nitrogen dioxide (NO2) in UK (2017) - GOV.UK document, and we already know it wants to see diesels banned by 2040.

That might seem a long way off, but the process has started now with financial disincentives for polluting vehicles and we can expect these to get more stringent and more widespread as time goes by.

And if you plan on doing any driving in France, be aware that many major urban centres now have their own ‘toxicity charges’ and you can be hit with hefty on-the-spot fines if you don’t display the appropriate Crit’Air clean air sticker and pay attention to local restrictions. You can find out more and get stickers at the official site: Air Quality Certificate Service - Ministère de la Transition écologique et solidaire

You won’t have to rush out and sell your smoky old diesel right now, but the writing is on the wall for ‘dirty’ cars, and knowing what’s coming will help you make a smarter choice for the next car you buy.

The key thing to know is your vehicle’s Euro emissions standard, because this is the basis for all current anti-pollution schemes. 

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What are the pollutants involved?

Current Euro standards quote four main pollutants:

CO – Carbon Monoxide 
This produces greenhouse gases and contributes to global warming, but it also interferes with the blood’s ability to transport oxygen, so it can be dangerous to those with existing health issues.

NOx – Oxides of Nitrogen 
Nitrogen oxides cause depletion of ozone layer and hence UV protection. NOx emissions are also also associated with acid rain and further reactions with hydrocarbons…

HC – Hydrocarbons 
Hydrocarbons react with nitrogen dioxide and sunlight to form low-level ozone. Ozone is great to have at high altitudes, but it’s not good at ground level. It’s a primary factor in smog and causes breathing problems. 

PM – Particulate matter
These are airborne particles that can irritate the skin and eyes and cause allergies. Fine particles have been shown to lodge in the lungs and cause breathing problems. 

What are Euro standards?

Each Euro standard describes maximum limits for a vehicle’s emissions, and later standards have different requirements for petrol and diesel cars – some also have supplementary amendments.

They might sound complicated, but the different Euro standards have been introduced chronologically, so each Euro standard can be seen as a ‘cleaner’ replacement for the one before. The higher the number, the newer the standard and the cleaner the vehicle.

Each standard is introduced in two stages. The first stage is a ‘type approval’ for the manufacturer, and the second stage applies to all new vehicles. Typically, these two stages are a year apart.

Euro 1 (EC93) – Jul 1992/Jan 1993)

This is when old-school leaded petrol was outlawed and we all switched to unleaded. Catalytic converters came in to reduced carbon monoxide emissions.

  • CO – 2.72 g/km (petrol and diesel)
  • HC+ NOx – 0.97 g/km (petrol and diesel)
  • PM – 0.14 g/km (diesel only)

Euro 2 (EC96) – Jan 1996/Jan 1997

Carbon monoxide, hydrocarbon and nitrogen oxides emissions were reduced, and this is when the petrol and diesel standards became separate.

* CO – 2.2 g/km
* HC+ NOx – 0.5 g/km
* PM – no limit

* CO – 1.0 g/km
* HC+ NOx – 0.7 g/km
* PM – 0.08 g/km

Euro 3 (EC2000) – Jan 2000/Jan 2001

Carbon monoxide and particulate limits were reduced and where hydrocarbon and nitrogen oxides emissions were previously combined for petrol cars, now they were measured separately.

* CO – 2.3 g/km
* HC – 0.20 g/km
* NOx - 0.15
* PM – no limit

* CO – 0.64 g/km
* HC+ NOx – 0.56 g/km
* NOx – 0.50 g/km
* PM – 0.05 g/km

Euro 4 (EC2005) – Jan 2005/Jan 2006

This marked the start of a diesel car clean-up, with reduced levels for particulate emissions and nitrogen oxides, and marks the first appearance of particulate filters on some diesel cars. 

* CO – 1.0 g/km
* HC – 0.10 g/km
* NOx – 0.08
* PM – no limit

* CO – 0.50 g/km
* HC+ NOx – 0.30 g/km
* NOx – 0.25 g/km
* PM – 0.025 g/km

Euro 5 – Sep 2009 (Jan 2011)

Euro 5 further reduced the limits for diesel particulate emissions, and now all new diesel cars required particulate filters. The new standard also introduced checks on the number of particles in an attempt to cut down on harmful very fine particle emissions.

Nitrogen oxides limits came down too. For the first time petrol engines got a particulate limit too, but applied only to those with direct injection engines. 

Euro 5 emission limits (petrol)

* CO – 1.0 g/km
* HC - 0.10 g/km
* NOx – 0.06 g/km
* PM – 0.005 g/km (direct injection only)

Euro 5 emission limits (diesel)

* CO – 0.50 g/km
* HC+ NOx – 0.23 g/km
* NOx – 0.18 g/km
* PM – 0.005 g/km
* PM – 6.0x10 ^11/km

Euro 6 September 2014 (September 2015)

This brought a big 67% reduction in maximum NOx emissions from diesel engines compared to Euro 5 and brings in similar standards for petrol and diesel. This led to some new technologies, including Exhaust Gas Recirculation (EGR),  NOx adsorbers, Selective Catalytic Reduction (SCR) and Cerium fuel additive to assist DPF regeneration.

* CO – 1.0 g/km
* HC – 0.10 g/km
* NOx – 0.06 g/km
* PM – 0.005 g/km (direct injection only)
* PM – 6.0x10 ^11/km (direct injection only)

* CO – 0.50 g/km
* HC+ NOx – 0.17 g/km
* NOx – 0.08 g/km
* PM – 0.005 g/km
* PM – 6.0x10 ^11/km

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

Following the scandal over rigged diesel emissions testing, the Euro 6d and Real Driving Emissions (RDE) tests were brought in from 1 September 2017.

A new WLTP (Worldwide harmonised Light duty Test Procedure) will apply to all new type approvals and a year later, from 1 September 2018, will apply to all new car registrations.

The additional RDE test will last between 90 and 120 minutes and take in a mix of 'normal' urban, rural and motorway driving. This will arrive in two stages – the first and more lenient stage (Euro 6d-Temp) offers more leeway for nitrogen oxides emissions (up to 2.1x the Euro 6 lab limit), while the more stringent second stage (Euro 6d) gives a leeway of just 1.5x the lab limit and comes into force on September 1st 2019.

How do I find out my car’s Euro standard?

From September 2018 the Euro standard for new cars will be shown soon the V5c registration document or online from [Get vehicle information from DVLA - GOV.UK](

For now, though, there’s no single authoritative source for this information. You can find out whether your vehicle meets the London T-Charge requirements (Euro 4) by using Transport for London’s online checker, but it doesn’t tell you want your car’s Euro standard actually is.

However, because the Euro standards have been introduced chronologically, you can work it out easily enough from our list above. If you know the year your car was made or registered, this will tell you its Euro standard.

What should I do now?

If you have an older, more polluting vehicle you don’t have to rush out and sell it straight away. It’s true that regulations in city areas are tightening, but if inner-city toxicity charges aren’t yet affecting you directly on a daily basis, you can probably afford to hang on until they do.

But you will need to know your current car’s Euro standard if you plan any journeys into pollution-controlled zones in the UK or overseas – and we can probably expect to see more and more of these emerging – and you might want to factor it in when planning your next car. 

Otherwise, if you don’t start paying attention to Euro standards, there’s a chance it won’t just be the environment that’s taking a hit, but your wallet too.