What is the proper tire?

 

one with alot of surface area and few waterways. It's a form of hydroplaning. An open differential will always spin the wheel with least traction/resistance. If neither wheel has traction, then they will both spin. If both have traction, neither will spin. If you have 500 pounds on the left rear and 300 on the right rear, the right rear will spin because it has less traction.