It’s backed by science. Due to the high temperatures in a Diesel engine, the amount of NOx produced is far higher than for petrol cars. NOx can be handled by a

It’s backed by science. Due to the high temperatures in a Diesel engine, the amount of NOx produced is far higher than for petrol cars. NOx can be handled by a catalysator using AdBlue or similar, so in theory Diesel engines could be clean. In practice the standards are routinely ignored by the car makers. The ruling allows banning cars that do not fulfil current standards, so a recent car is probably unaffected. However, the restriction could be lifted if only banning old cars proves insufficient. Then, newer cars could be affected.