Registration here is based on the number of cylinders your car has.

I think it should be based on mass, so that it is in line with how damage the vehicle does to the road. You can see that's the case with vans and utlities, but not for passenger vehicles.

Some four cylinder passenger vehicles weigh more than 1500kg, let pay $300 less, though, they'd be doing more damage to the road, for each kilometre they drive than a ute or a van. I guess the difference is that the utes and vans are always LOADED.

And still, the roads are pot-holed nests of terrible ride quality.