It's worth mentioning that the Euro 7 standard has not yet been formalised, however the proposal is that it will require CO of less than 0.3g/km (currently 1.0g

It's worth mentioning that the Euro 7 standard has not yet been formalised, however the proposal is that it will require CO of less than 0.3g/km (currently 1.0g/km) and NOx of less than 0.03g/km (currently 0.06g/km).