Minimum emission standards
Petrol: Euro 4 (NOx)
Diesel: Euro 6 (NOx and PM)
The ULEZ is enforced based on the declared emissions of the vehicle rather than the age. However:
- Petrol cars that meet the ULEZ standards are generally those first registered with the DVLA after 2005, although cars that meet the standards have been available since 2001
- Diesel cars that meet the standards are generally those first registered with the DVLA after September 2015