Delta is the capital city of Velocitron.
Delta was the largest city on Velocitron, built on the interchange between several of the planet's many highways. It hosted the great Speedia race that determined the planet's next leader. In addition to its central straightway, it boasted twelve other racetracks, in addition to a large central hangar for pit crew modifications.
Ransack led Optimus Prime, Bumblebee, Jazz, Silverbolt, and Perceptor to Delta, where they met Override and learned of the many resource shortages that plagued Velocitronian culture. However, they had arrived just in time for the Speedia race, which took place in the center of Delta. The generally favorable reception that they received allowed Optimus to land the Ark there. However, when Ransack instigated a war, the Autobots fled at Override's request. Delta would later be used as a temporary base of operations for both the Star Seekers and the Decepticons.