Another development in trucking efficiency that seems really interesting is the Achates opposed piston two stroke. If their materials are accurate, through fluid modeling they've achieved a massive efficiency boost and emissions exceeding regulatory targets without urea injection. In a piston ported two stroke.

https://www.ccjdigital.com/regulations/article/15291029/acha...

This is the most recent news I can find about them, though, so unclear if these engines will ever be produced for road vehicles:

https://www.govconwire.com/articles/ga-asi-david-alexander-a...

See also: https://achatespower.com/resources/

I was hoping we'd see these engines running generators in Edison trucks one day.