The State of New Jersey uses age and weight:
Basic automobile registration fees
Weight Class Model Weight Fee
1 1970 or older Under 2,700 lbs. $35.50
2 1970 or older 2,700 lbs. - 3,800 lbs. $44.50
3 1970 or older Over 3,800 lbs. $65.50
4 1971 – 1979 Under 2,700 lbs. $38.50
5...