Clean air zone-compliant cars

With clean air zones now in force in Birmingham and Bath, a ULEZ-compliant car might be useful if you need access to city centres

Simon Ostler
Aug 9, 2021

Following the arrival of the ultra-low emission zone (ULEZ) in central London back in April 2019, other cities across the UK are planning to introduce their own emission restrictions. These new zones are known as clean air zones (CAZ) and there is a long list of cities in Britain with plans to introduce the initiative.

Clean air zones in Birmingham and Bath are now in force, while a zone Portsmouth is due to come into operation in late 2021, followed by several others in 2022.

Clean air zones are intended as a deterrent to drivers of high-emission vehicles from entering densely populated areas and, by extension, encourage them to buy a newer, cleaner car. Exact penalties for the zones will depend on the city, but using Birmingham as an example, drivers of cars that don't meet the restrictions will be obliged to pay an £8 fee to enter the CAZ. Larger HGVs, buses and coaches will be subjected to a much more substantial £50 daily fee.

In general terms, cars likely to be charged will be diesel models that do not meet the current Euro 6 emissions regulations that became mandatory from September 2015, and petrol cars older than 12 years. You'll want to check your own cars' emission rating before venturing into a city with a clean air zone - it can usually be found on your V5 certificate.

Clean air zone-exempt cars

Petrol cars registered since January 2006

These emission restrictions have been designed to reduce the volume of harmful emissions being produced by cars in city centres. The number crunchers have decided the threshold for petrol engines should be the Euro 4 emission standards that were introduced in January 2006. 

Therefore you can be fairly certain your car will meet the CAZ requirements if it was registered since then, but it is always worth double checking to make absolutely sure. 

All of the petrol cars available on BuyaCar are certain to meet Euro 4 standards, so we've got you covered if you're in need of a new petrol car that meets the CAZ requirements.

Diesel cars registered since September 2015

In the case of diesel cars, they have received some damning press in recent years for the harmful nature of their exhaust emissions. So it is no surprise that diesel cars in particular have been targeted by these new restrictions. 

In order to comply with CAZ requirements, a diesel car must meet with the very latest Euro 6 emission standard, so only models that have been registered since September 2015 will be eligible for free city travel.

There are a small number of exceptions, where certain diesel models registered prior to Euro 6 standards may still comply, but you'll need to check carefully on your V5 certificate to be sure. The list includes the Mazda CX-5, the Audi A3, Mercedes A-Class and Vauxhall Astra, and you can see the full list here.


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