[ylk1]

Most of the production engines still use tumble flow combustion

For reference: Nissan e-power with recuperation ~50%: https://www.nissan-global.com/EN/INNOVATION/TECHNOLOGY/ARCHI...

Mahle ~45% with pre-chamber: https://www.mobilityengineeringtech.com/component/content/ar...

Toyota dynamic force engines ~40% : https://www.thedrive.com/tech/18919/toyota-develops-worlds-m...

Toyota's newest engines claim even more: https://global.toyota/en/newsroom/corporate/40850156.html

Honda hybrid ~40%: https://hondanews.com/en-US/honda-automobiles/releases/relea...

Startup Carnot engines claim 70% efficiency: https://carnotengines.com/technology/

[rasz]

>Mahle ~45% with pre-chamber

That looks deceptively simple and counterintuitive. Mentioned Honda CVCC injects fresh air/fuel mixture into pre chamber. Mahle passive doesnt at all. How does it accomplish detonation in the first place? How does the fresh air/fuel get into the chamber thru those tiny nozzle openings? there must be something they arent showing like additional channel leading close to intake valve.

[cedws]

What’s the catch with the Carnot engine? If if’s real then surely this would be a global news worthy breakthrough?

[tweetle_beetle]

> Carnot is targeting the hardest to abate sectors including [long haul] marine [transportation], heavy-duty vehicles and primary off grid power.

Even if great advances were being made, these are not very interesting sectors to the vast majority of people and the industries have massive inertia. Presumably Carnot's therefore unlikely to be grabbing headlines.

[cedws]

But such an improvement in efficiency would surely reduce fuel costs, which matter a lot to consumers, though maybe not in the US where it’s cheap.