From article <1993Apr5.200048.23421@ucsu.Colorado.EDU>, by lorenzo@rintintin.Colorado.EDU (Eric Lorenzo):

--Let me put it like this.  The only similarity between the three models
  is the "300", or 3-liter engine displacement.  Actually, the SC300 (the
  coupe) and the GS300 (the funky-looking new sedan) share the same 3.0
  liter inline-six, and the ES300 (popular small sedan) uses 3.0 V6 shared
  with the Camry.  The SC300 is a luxury/sports coupe, the GS300 is the new
  luxury sedan, and the ES300 is the base executive sedan.  All three look
  completely different.

--Aamir Qazi
-- 