The benchmark article we're replying to shows that Grok token usage is at least on par with the latest OpenAI models [1], and significantly cheaper per token:

https://artificialanalysis.ai/models/grok-4-6#token-use

So depending on how you want to define "token efficiency", Grok is either tied with OpenAI, or in the lead.

[1] Though I grant that 4.6 appears to be wordier, on the order of Terra max.