The Great Upgrade is a significant event in Transformers history that occurs in the timeline between The Transformers original cartoon and the Beast Wars series. The details behind this event are unclear as it is only brought up once in the Beast Machines series by Optimus Primal while visiting the ruins of Iacon, who referred to it as "the great upgrade from Autobot to Maximal". This would likely have also been the point at which certain Decepticons, such as Ravage, were turned into Predacons. The upgrade emphasized fuel efficiency from reduced size, similar to the Micromasters.