evidence: However, petrol vehicles that meet the Euro 4 emissions standard are exempt from the ULEZ charge. This means that if your petrol vehicle was registered after 2006, you can drive in the ULEZ without paying the daily charge. [...] Petrol cars that are exempt from ULEZ are those which meet the Euro 4 standard or higher. Euro 4 emissions standards were introduced in 2005, so petrol cars which were registered after this date with a petrol engine and a catalytic converter are exempt. [...] To summarise, cars with diesel engines that meet the Euro 6 standard for NOx emissions are exempt from the ULEZ. - When did ULEZ expand to cover all of London?