There's already a 100 octane mod (
http://forum.1cpublishing.eu/showthread.php?t=25260 )
Luthier has alreasdy indicated there is no impotus from the devs to intoduce 100 octane into COD. It's just a couple of text file changes to impliment 100 octane, so the modders will be all over it once the game is opened up to community-made content.