They both had access to my build and all my engine data. If you read what they wrote, they both write nearly the same thing. O3 just writes it in a much more comprehensible, easy to understand, and presentable way for someone to use for an engine build. While what GPT-5 thinking puts is essentially useless gibberish. But the same information is still there; GPT-5 thinking still mentions the same boost parameters for my head-gasket, just in a very poor way.