How would a zero emissions car be paying more in fuel?
And, where's the downside? The current system is geared as a punitive system so higher polluting cars pay more tax, allegedly to encourage people to buy economical cars for the environment (definitely not to raise money for government coffers). Shifting it to fuel if anything magnifies this. For example, with 15p/litre tax:
Fred drives 8,000 miles a year in his 1.6 Ford Focus at 40mpg and pollutes the environment with 908L petrol burnt. He pays
£145 VED and would pay £121.07 in extra fuel duty if VED were put on fuel.
Steve drives 1,000 miles a year in his Porsche 911 Turbo 3.8L at 20mpg and pollutes the environment with 227L petrol burnt. He pays
£485 VED and would pay £30.27 in extra fuel duty if VED were put on fuel.
Andy drives 25,000 miles a year in his BMW 320d at 60mpg and pollutes the environment with a whopping 1891.67L diesel burnt. He pays
£20 VED and would pay £265.56 in extra fuel duty if VED were put on fuel.
These are the simple matters with only one car. Putting the VED on fuel still encourages people to buy more efficient cars because if Andy drove his 25,000 miles a year in that Porsche 911 Turbo he would be using 5675L fuel instead of <2000 which would have a huge impact on his wallet. With VED on fuel, however, he pays more than the other two drivers despite having a more economical car, simply because his car emits the most emissions due to being used more.
Then we get to Frank.
Frank has a 1.6L Focus and also a Porsche 911 Turbo. He drives 10,000 miles a year. He can only drive one car at a time. However, he has to pay VED on both cars totalling
£630 VED. If VED were put on fuel, he could travel those 10,000 miles for an extra £302.67 in the Porsche, or an extra £151.33 in the Focus.
I've just picked a number out of thin air for fuel duty but the government knows how many litres of fuel are sold in the UK and how much VED is currently paid so it can't be hard to work out the right amount of tax to add per litre.
All this does is illustrate how unfair the current VED system is, penalising drivers in cars like the 1.6 Focus who pay
7 times the amount of road tax as many company rep-mobiles despite, in this particular example, emitting half as much CO2 (ignoring all the other greenhouse gases because obviously they don't count

) as the 320D.
And those people with more than one car simply have their VED doubled despite essentially halving their total mileage on each car.
Yes, a low emissions car would pay more in tax than they do through the VED system, if they use a large number of litres of fuel per year.. surely that is what counts? Pay for what you use, not what you
might use?
The VED system could work relatively well if everyone did exactly the same mileage. People don't.