'nother wheel thread

[wolfracesonic]

The 'Under wheeled thread' got me thinking why we now have such a wide range of humongous wheels, 19'' and 20'' not being uncommon, even diesel hatchbacks running 17'' wheels even in poverty spec. Up until the mid 80s even supercars seemed to be limited to 16'' till the 512TR appeared with 17'' wheels. Was there some giant leap forward in wheel/tyre manufacturing technology or did designers just not consider anything larger than 16''?