Here's something I never thought of: I was walking by my car today and was able to see over the front passenger side tire all the way through to the snow on the other side of the car. Is something missing? I checked other cars and in no other case could I see all the way through. I'm suspecting something that prevents grit from getting from tires to engine has broken or fallen off. This is a Honda CRV.
See question, re: tires.