Doors by far. House doors, barn doors, closet doors, cabinet doors, dollhouse doors, vehicle doors, the door of a cuckoo clock, microwave door, oven door, mailbox door, and far more.<p>Most tires are for things that also have a door (a 4-door sedan had the same number doors as tires - oh, and a glove compartment door; a large plane has at least 4 passenger and catering doors, the cockpit door, and the doors to the bathrooms) or are associated with a door (a wheelbarrow might be kept in a shed with a door; a bicycle might be kept in a locked room).<p>As I recall, Lego is the biggest tire producer in the world at 700 million per year. But they also produce a larger variety of doors.<p>Excluding toys, I count at least 60 doors here I live, and about 20 tires.<p>Had you asked about "wheels" rather than "tires", then I suspect there are far more wheels than doors. A car engine has a lot of wheels in it.