The simplest reason? My guess is capitalism. If every car model available for a consumer to purchase has the same advertised speeds, the competition between ma

The simplest reason? My guess is capitalism. If every car model available for a consumer to purchase has the same advertised speeds, the competition between manufacturers will slowly dry up. I'd guess this would result in less cars being sold. Would manufacturers compensate by competing in other areas to attract buyers? Why buy a Kawasaki Ninja H2SX when you could buy a Yamaha N Max...