Euro Emissions Standards: A Simple Guide

If you’re thinking about buying your next car, you’ve probably heard about Euro emissions standards. They were introduced to help improve the air quality across the UK and Europe, and they’re worth getting your head around before you decide on a vehicle.

Since they first appeared in 1992, these standards have made a real difference to our air and our health. But what exactly are they, and what do they mean for you when you’re looking for a used car?

Let’s dive into the world of Euro emissions standards and find out why they’re so important.

What are the Euro emission standards?

Think of Euro emissions standards as a set of rules for car manufacturers. Their main job is to limit the harmful stuff that comes out of a car’s exhaust, making vehicles cleaner and kinder to the environment.

The first standard, Euro 1, rolled out in 1992. It meant that all new cars had to have a catalytic converter fitted. Since then, the rules have been updated several times, with each new standard getting a bit stricter on vehicle emissions.

Why were the Euro emission standards introduced?

The standards were brought in to cut down on the harmful toxins in the exhaust fumes from petrol and diesel cars, vans, and motorbikes. These fumes contain things like nitrogen oxides (NOx), carbon monoxide (CO), and other tiny particles that aren't great for the planet or for us.

And the good news is, it's working! Data shows that since the early 90s, carbon monoxide levels from cars have dropped significantly. We've also seen big reductions in nitrogen oxides and other particulate matter, which is great for our lungs. For example, modern diesel cars are now fitted with diesel particulate filters (DPFs) that capture almost all of the sooty particles from the exhaust. It's a huge step forward for cleaner air.

What Euro standard is my car?

The Euro standard your car meets usually depends on when it was first registered. If your car is older than the standard it was meant to meet, it doesn’t have to comply.

Here’s a quick guide to help you figure it out:

*Some cars sold before 1st September 2016 might still have a Euro 5 engine. It's always a good idea to double-check with the seller.

Why do I need to know my car’s Euro emission standard?

Knowing your car's Euro standard is useful for a couple of reasons. First, it gives you a better idea of what to expect from the car. For example, knowing that all Euro 5 and 6 diesel cars must have a DPF helps you know what to look for when checking a used car, as these can sometimes be a point of failure on an MOT.

More importantly, it affects where you can drive without paying a charge. Big cities like London, Birmingham, and Bristol have introduced Ultra-Low Emission Zones (ULEZ) to tackle pollution. Whether you have to pay the daily charge depends on your car’s Euro standard.

As a general rule, petrol cars that meet Euro 4 standards and diesel cars that meet Euro 6 standards are exempt from ULEZ charges. Fully electric cars are exempt too, of course. If your vehicle doesn't meet these standards, you'll need to pay a daily fee to drive in these zones.

How to get proof of your vehicle’s Euro emission standards

Besides using the registration date, there are other ways to confirm your car’s Euro standard. For newer cars in the UK, you can find this information in section D of your V5C logbook. Sometimes, you can also find it on a sticker inside the driver or passenger door frame.

If you’re buying a car from a dealer, they will be able to give you this information. While our table is a good guide, checking the official documents is always the best way to be certain.

Euro 1 emission standards

Introduced in 1992, Euro 1 was the game-changer. It required all new petrol cars to use unleaded fuel and be fitted with catalytic converters to slash carbon monoxide emissions.

Euro 1 emission limits

Euro 2 emission standards

In 1996, Euro 2 arrived and set different limits for petrol and diesel cars. It tightened the rules on carbon monoxide and other pollutants for both fuel types.

Euro 2 emission limits – Petrol

Euro 2 emission limits – Diesel

Euro 3 emission standards

January 2000 saw the arrival of Euro 3. The testing process was updated, and for the first time, separate limits were set for nitrogen oxides (NOx) in diesel engines and for hydrocarbons and NOx in petrol engines.

Euro 3 emission limits – Petrol

Euro 3 emission limits – Diesel

Euro 4 emission standards

By 2005, diesel cars were becoming very popular. The Euro 4 standard brought in tougher limits specifically for diesel emissions. This is also when many diesel cars started being fitted with particulate filters to trap soot.

Euro 4 emission limits – Petrol

Euro 4 emission limits – Diesel

Euro 5 emission standards

Euro 5, introduced in 2009, put an even bigger focus on diesel cars. The limit on NOx was cut significantly, and DPFs became a requirement for all new diesel cars to meet the rules, capturing 99% of nasty particles.

Euro 5 emission limits – Petrol

Euro 5 emission limits – Diesel

Euro 6 emission standards

Euro 6 was introduced in September 2014. It brought another major reduction in NOx from diesel cars, cutting the limit by a further 67%. Many modern diesel cars now use systems like AdBlue (a type of Selective Catalytic Reduction) to turn harmful emissions into harmless nitrogen and water.

Euro 6 emission limits – Petrol

Euro 6 emission limits – Diesel

Euro 7 emission standards

The next chapter, Euro 7, was set to be implemented from 1 July 2025 but has since been pushed back to November 2026. It will introduce the strictest limits yet for all new petrol and diesel cars.

Euro 7 will not only tighten the limits on exhaust emissions but will also look at other sources of pollution for the first time. This includes particles from brakes and tyres. It will even assess the lifespan and performance of batteries in electric and hybrid vehicles.

Don't worry, though. Car technology is always improving to keep up with these standards. New cars will even have clever sensors to spot any engine faults that might cause emissions to rise, so you can get them fixed quickly. And just like with previous updates, cars already on the road won't need to meet the new Euro 7 rules.

Frequently Asked Questions

What is the current Euro emission standard?
Right now, the latest Euro emissions standard is Euro 6 for both petrol and diesel cars. If you’re planning on driving in a ULEZ zone, you’ll need at least a Euro 4 petrol or Euro 6 diesel vehicle to avoid paying the charge.

What cars are ULEZ compliant?
For petrol cars, ULEZ compliance means meeting the Euro 4 emissions standard or higher. Diesel cars need to meet the Euro 6 standard. And here’s some good news—electric vehicles are completely exempt from ULEZ charges!

Can I make my car Euro 6 compliant?
It’s possible for some cars, but not all. Upgrading a diesel from Euro 5 to Euro 6 can sometimes be done using a conversion kit (which adds new tech like a particulate filter and exhaust gas recirculation). But it can be quite pricey, and your car will need a fresh check from the DVSA to confirm it meets the rules. For petrol cars, making this upgrade is usually too costly to make sense.

Does Brexit have an impact on Euro emission standards?
No worries here—Euro emissions standards are sticking around in the UK, even after Brexit. The UK is still committed to keeping our air clean, so these regulations remain in place.