Realistically we should be taxing by weight and miles driven as the former causes the most damage to the roads. At that point the propulsion type and efficiency don’t really matter. EVs actually would be taxed more given that they’re heavier, but it’d also proportionately tax trucks and larger vehicles correctly at that point.
You could easily implement it with a yearly odometer reading with your registration or inspection and every car has a GVWR registered with it.