@ImagineThat So the additional weight fee is imposed without regard to weight?
@walterbays I was not being clear. Heavier vehicles, of course, wear out pavement and should be taxed accordingly. In WA this is accomplished by an "additional weight fee"--which for some vehicles is for weight over 4000 lbs, and for others is for weight over 0 lbs.
If your car weighed 3999 lbs and its first registration was 7/1/2016, you pay no additional weight fee; if your car was literally weightless but was first registered after that date, you pay a $10 "additional weight fee."
@walterbays Why should it have anything to do with weight?