Grok 4.5: Elon Musk's AI Secretly Tested at SpaceX & Tesla

Elon Musk's xAI has secretly started testing its new AI model, Grok 4.5, within SpaceX and Tesla. This is a significant jump for xAI, as Grok 4.5 is roughly 50% larger than its predecessor, Grok 4.4. What's interesting is that this model went live inside Musk's companies before any public demo. Musk confirmed the news himself on X after the internal launch. Grok 4.5 is built on xAI’s new V9 foundation model. It finished training on May 26, 2026. Musk claims early evaluations show Grok 4.5 performing close to, or even ahead of, Anthropic’s Claude Opus 4.8. However, independent benchmarks have not yet confirmed this comparison. The decision to test Grok 4.5 at SpaceX and Tesla appears deliberate. Both companies offer demanding, real-world engineering problems that serve as a strong proving ground for the AI. This internal testing could help refine the model's capabilities before a wider release. This move happens during a competitive period in the AI industry. Why this matters: it signals xAI's strategy to validate its AI through practical applications in complex environments.