"Hot Rodimus" is what Hot Rod has always been called in Japan, ever since 1986. In Japan Rodimus Prime is called "Rodimus Convoy."

"Rodimus" has become the standard name for Hot Rod now because Hasbro no longer holds the legal rights to the Hot Rod name. When Hasbro released their Hot Rod reissue they called him "Rodimus Major" which was a suck name, so now they just call him "Rodimus." Canonically Hot Rod's name had become "Rodimus" at the end of the Autobot-Decepticon war (re: Pax Cybertronia).