Is Chat GPT-3.5-turbo enabled for both Free and Plus users?

I’d like to clarify the difference between ChatGPT and ChatGPT Plus. As I see, by default both subscriptions call GPT-3.5 as the fastest available model. As of today, there’s no dropdown letting me select regular 3.5 or 3.5-turbo, but I noticed that Plus’ version of 3.5 responds significantly faster than the free one. Is “Turbo” version only available in plus? With the new UI I cannot answer that easily.