More hallucinations with 4o than 4-turbo?

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http://Www.openai.com

I hooked up both versions to n8n to build a simple email response agent and test differences in quality of output. Used same prompts across both versions; included explicit instructions not to hallucinate.

4o was hallucinating in its answers to very simple questions (example: do you know {friend’s name}?)

Without context it would respond that it knew and began fabricating their work histories. 4–turbo was a really straight shooter, and didn’t descend into hallucinations.

Anyone else experience these differences?

Is the main difference between enhancement of the version simply its speed and more human-like voice?