We tend to think of tires as big circular hunks of black rubber that just roll down the road. We don’t think about them much until something goes wrong and you’re stuck waiting for roadside assistance or digging the spare out of the trunk.We tend to think of tires as big circular hunks of black rubber that just roll down the road. We don’t think about them much until something goes wrong and you’re stuck waiting for roadside assistance or digging the spare out of the trunk.