But a tread pattern will not "grip" dirt, grime and oil. That's the point. The edge of a groove in a tire won't do diddly squat to hold onto a piece of asphalt that has been saturated with antifreeze. The edge of a groove wont bite the fine silt floating on the road surface.

A hard surface will bite a tire or it won't. Adding grooves to a tire just offers the road less to bite.

The illusion that people are under is that a tread pattern or groove will "Bite" an unstable surface. It won't. Think of riding around a corner covered in dry fall leaves. Tread pattern or slick, you are going down.