Does a single Euro VI bus really release less NOx than a euro 6 diesel car?

A transport expert claimed that a Euro 6 car has fewer NOx emissions than a Euro VI bus, surely this cannot be correct?!

https://en.wikipedia.org/wiki/European_emission_standards

Euro 6b (diesel car) - 0.080 g/km of NOx

Euro VI (bus) - 0.46 g/kWh of NOx

Need to convert from g/kWh to g/km. Assuming 1 gallon is equal to 36kWh and the bus does 7 miles per gallon.

7 m/g = 11.2km/g NOx/g = 0.46g/kWh 0.46g/kWh * 36kWh/gallon = 16.56g/gallon 11.2km/gallon / 16.56g/gallon = 1.49g/km

I make it that the bus would be 1.49g/km in comparison to the car that would be 0.08g/km. I make the single bus 18.6 times more polluting than a single car.

Is this correct?

• Is it possible that they meant per passenger?
– LShaver
Mar 31 '21 at 14:22
• Yes, I realised that when I was writing this! However, I wrote this spreadsheet that shows, based on emission limits alone, that the difference per passenger is not clearcut. For example to have parity between in emissions between a bus passenger & a car passenger (1.4 per car), the bus would need to achieve 8mpg with an average of 23 passengers...for CO you would need an avg of 32 passengers...these are very high occupancy rates. docs.google.com/spreadsheets/d/… Mar 31 '21 at 21:59