Concept power units from 2030

[Dr. Acula]

This supports your view

https://www.autosport.com/f1/news/f1-ma ... /10757765/

Though Audi still saying they want a high efficiency hybrid engine.

High efficiency would, surely, rule out any N/A engine?

I don’t think so!

Toyota which has been the only car manufacturer producing fully hybrid cars always uses NA engines along with batteries and CVTs! So I don’t think NA engines mean low efficiency…

Maybe that’s why they don’t have one foot in F1 (I mean with Haas).

You have to differentiate between racing and road use. Yes, a charged induction system would increase efficiency, if it runs on nominal charge pressure. In racing that's the case probably 60-80% of the time. If you crawl through a city, you may never reach nominal charge pressure. Which means you're stuck with a engine that in most cases has a lower compression ratio than a NA-engine would have, which means in this scenario, the charged engine is less efficient. Also, the induction charging system adds weight and needs space. Which makes the car as a whole a tiny bit less efficient.
In road applications, it's not just the engine, it's the whole car as a system that determines how efficient it is.

[gruntguru]

Even in road use, a "hybrid" transmissions allows the ice to operate at its peak efficiency for most or all of the time. The most efficient package would be a charged engine. A charged engine will also be lighter than NA and have lower friction losses.