Cars should be taxed based on their potential for road wear, which is calculated approximately by their weight to the fourth power.
Adding such a tax, where every vehicle paya relative to what they do to the road surface they roll on, would instantly make all SUVs unviable. It would also increase the incentives for shipping freight by rail by an incredible amount.
Dude, we are still stuck with half of America thinking more CO2 is good because it's "extra plant food". This policy you suggest would have them countering saying they should pay less for helping to feed the forests with their vehicle's emissions.
It's a great solution, but I don't know how we could get it passed.
Cars should be taxed based on their potential for road wear, which is calculated approximately by their weight to the fourth power.
Road wear comes from weight and power, so does pollution. Add size to the equation and you can estimate a cars dangerousness. Look only at size and you can see a cars damage to urban spaces. Hence, private vehicles should be taxed based on their size, weight and power. Bonus points for tire width, because tires are a non-recycable environmental problem and super-wide tires add nothing to the world but damage.
As someone who lives in a country that actually has this system. No. It's a shitty system. It results in old shitty cars that pollute like insanity. Some cars are more economical and safer than some badly built cars with less safety features and those safer cars are actually punished with this system.
You are literally better off buying an old banger that is falling apart and a road hazard than a new car because of our stupid tax system. And the people who drive SUVs here are usually rich and don't care about higher road tax.
You'd need some carve out for electric vehicles, they are super heavy compared to a gas car of the same size.
(Assuming you want to encourage electric over gas)