Tax exemption under threat?

[warch]

As I understand it tax bands target petrol engined cars which emit higher levels of CO2 and ULEZ tend to target older petrol cars and all but the newest diesels because of particulates. 

[willswitchengage]

2 hours ago, EightMegs said:

CO/km should be negligible if you have a working catalytic converter, and CO2 per kilometre doesn't have anything to do with the ULEZ, Euro 4 is about particulates, unburnt hydrocarbons, and nitrogen oxides coming out of the exhaust. Compare the MOT exhaust gas analysis from a 25 year old Civic with a modern one and I think you'd be surprised at what's coming out.

Typo! I meant gCO2/km