Insurance what a piss take.

[BBROWN1664]

Got it, the government can keep their environment cash cow.
Low co2 transport use a fuel with a green dye in it with low tax added.
Med co2 use fuel with a blue dye
high co2 use black dye

BUT.....
A high CO2 vehicle will use more fuel than a low CO2 vehicle anyway so no need to use different dyes. Just use the same fuel, pay the same amount of additional tax per litre and the higher CO2 vehicles will pay more due to buying more fuel. (unless they don't get used much in which case it makes it fairer too)