The Fiat 500 is named that because the size of the engine is roughly 500cc. The original 1936 Fiat 500 (Topolino) had a 569cc engine. The 1957 Fiat 500 had a 479cc engine. The New Fiat 500 from 2007 is named that because it's styling and fun character are the modern day interpretation of the older cars. Hope this helps, best regards, Chris http://fiat500usa.blogspot.com/