I didn't see the actual answer to the thread title anywhere in this thread.
In the early days of cars and relatively modern wheels/tires, car makers were going in the direction of having custom sizes of wheels/tires for their cars. This would lock consumers into buying replacement wheels/tires (many back then due to state of roads and state of wheels/tires!) from the original car company or at least into buying very obscure and specialized sizes from independent sellers (which was not practical). So car companies were on their way to "tethering" high-margin replacement wheels/tires to the original cars.
The Tire and Rim Association was created in the U.S. to standardize sizes and specs for tires and wheels. For once the good guys won, and TRA was tremendously successful at bringing this standardization and sanity to the automotive industry. TRA standards and specs are still the bible today for any car company bringing a new vehicle model to market or introducing new wheel sizes for an existing model. Consumers can buy the same specs of replacement tires for their Ford or Toyota or VW.
I think the success of TRA in the U.S. led Euro and Asian companies to adopt this system, which also made additional sense as car export/import between continents became more common. So today, all automotive/tire companies "think" of tire sizes and specs in terms of old U.S. (TRA) units, even though the detailed Engineering drawings of tires and wheels are now of course in normal SI/metric. Just like how current F1 tires are made for 13-inch wheels, but the rules are spec'd in mm. All significant tire and car companies in the world are members of TRA.
So TRA (and no I have no connection to them) has saved the world truly vast amounts of money and headaches over the last 100+ years. One of humanity's most successful organizations that nobody has heard of.
http://www.us-tra.org/aboutTRA.html