What are Euro 6 emissions standards? Why you need to know

The latest emissions standards - and why they aren't up to scratch: all you need to know about Euro 6

BuyaCar team
Jan 31, 2018

If you've looked into buying a diesel car, then there's a good chance that you've seen mention of Euro 6.

It's the name of the latest emissions regulations, which apply to every new car sold in Europe since September 2015 (some older cars also comply). The standard set tough new limits for certain toxic emissions in diesel exhaust gases.

If you are looking for a diesel and can afford the cost, it's better to buy a Euro 6 car because these are the cleanest diesel vehicles available and are less likely to be affected by any future diesel charges. Euro 6 owners don't have to worry about London's T-Charge and the forthcoming ULEZ emissions charges, which impose a fee for anyone driving older and dirtier diesels into the capital. Euro 6 car owners are also likely to be exempt from similar schemes introduced in other British cities.

Euro 6 regulations also apply to petrol cars, including hybrids, but aren't a huge step beyond earlier Euro 4 and Euro 5 emissions standards, which were already strict for petrol vehicles. That's why these older petrol cars won't be affected by emissions charges that apply to diesel cars of the same age.

Cars are tested in a laboratory to ensure that they comply with the Euro 6 regulations but studies carried out on public roads have revealed that many Euro 6 diesels emit significantly higher levels of pollutants in the real world. Petrol cars tend to be much cleaner. The tests are currently being toughened to ensure that newer Euro 6 cars maintain low emissions when they are driven on the road.

Why Euro 6 emissions regulations matter

Governments and councils are increasingly taxing and charging cars, based on their Euro emissions standard. By 2021, up to 27 cities could set up clean air zones that would penalise cars not meeting Euro 6 standards; London's Ultra Low Emissions Zone (ULEZ) comes into force next year and will charge non-Euro 6 diesel car drivers £12.50 a day if they go into the centre of the capital. The rules are different for petrol cars and only affect vehicles older than 12 years.

But the government is already looking beyond the current regulations towards a tougher Euro 6 standard, which will test cars driven on public roads, called Euro 6d

In the autumn 2017 budget the Chancellor announced an increase in the first year tax rate of new diesels first registered from 1 April 2018 that don’t meet the Euro 6d standard. Worryingly for car buyers, there is no indication when these vehicles will go on sale.

Not only do drivers of non-Euro 6 cars face the possibility of city centre charges, the value of their cars could decline as a consequence. Diesel car values began falling faster than those of petrol cars earlier this year, according to the car valuation firm CAP HPI. That trend appears to be accelerating, with some nearly new diesel cars selling for less than their petrol equivalents, despite costing more as new cars.

On the other hand, their lower prices are making them more attractive to used car buyers unfazed by the possibility of pollution charges and demand is strong for the most desirable diesel models.


Identifying a Euro 6 car

It’s clear it’s becoming increasingly important to know what Euro standard the petrol or diesel car you’re buying conforms to. Ideally, it would conform to Euro 6 but since this only became mandatory on all new cars from September 2015, many cars registered before that time – so those on 2015 (15) registration plates and earlier – might only be Euro 5.

The exception is all-new models registered from September 2014. These will be Euro 6 compliant, as are models such as the Mazda CX-5 that became so as far back as 2012.

Like many retailers, BuyaCar publishes the Euro standard of each used car in the technical information that accompanies each listing. Be sure to check it to avoid the possibility of being hit with pollution charges in the future. If it's a key concern, you should ask for this to be double-checked.


Euro emissions standards

Euro 4 – from January 2005 on all-new models and January 2006 on all new cars
Euro 5 – from September 2009 on all-new models and January 2011 on all new cars
Euro 6 – the current standard came into force on all-new models in September 2014 and all new cars from September 2015.

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