Groundbreaker is a fictional character from the Transformers series. He is an Autobot Pretender. ==Transformers: Generation 1== Groundbreaker is a Pretender Autobot who turns into a rocket car which can reach speed of mach 1. He his a mech of action who wants everything done now and is happy to be the one to do it. He is also brutally honest. His ... Found on http://en.wikipedia.org/wiki/Groundbreaker