No, not immortal. We can die of age-related illness if we aren't killed. [Even if he hadn't experienced it, Drift notified him of Ratchet's funeral not too far in the timeline. Not even a great medic can stop old age.] I'm over five million years old. Some of my colleagues were only a few hundred years old. Few remain from the earlier days of Cybertron. But compared to many organics, it does seem like immortality.

[Unfortunately, this does not translate to maturity and many Transformers are stuck in dramatic teenager and young adult mindsets.]

Better that we met now than earlier, I take it? Or could we have changed knowing each other?