In a tire manufacturing landscape thick with companies that are over a century old, the world's biggest tire maker is a relative upstart with just fifty years under its belt. The Lego Group , yes, Lego, makes more rolling stock than anyone, molding 381 million wheels each year, with sizes as small as a half inch and going up to 4.2 inches in diameter.It turns out tires are an integral part of the Lego success story. Lego had been producing kits for more than a decade before the 1962 debut of set #400 . That kit included the first version of the now-familiar Lego tire and quickly became a best-seller, accounting for 820,400 sales all on its own in 1967. Before the Lego wheel arrived on the scene and kicked off its revolution, cars in the Lego realm were pre-molded affairs , and some clever children created 8-bit-looking wheels with the Lego bricks themselves.With such a long history of building beloved toys, you'd think Lego would tie up with a manufacturer of car tires and put the Lego brand on tires we can put on our daily drivers. Make ours Z-Rated, please.