Cybertronian Radial

Cybetron Radial (or Radial Cybertron) is a brand of tire used by numerous Transformers, most notably during their Alternators upgrades. Apparently, while they were allowed to use licensed cars, they still had to keep rolling with their Cybertron Radial original tires. Maybe they had a trademark issue...?

Optimus Prime, on the other hand, had no problem switching to the Desert Dog Formula brand.

From Teletraan I: The Transformers Wiki, a Wikia wiki.