CnC Tiberian Dawn vs Red Alert game engine differences

[redalertfan2]

This has probably been asked before, but I did a search and only saw that someone mentioned that Red Alert uses a "similar engine" as Tiberian Dawn.

With the release of the game engines behind Command and Conquer: Tiberian Dawn and Red Alert on GitHub     recently, were there any notable game engine / AI differences?

Or was Red Alert just using Tiberian Dawn's engine with different graphics and support for larger maps?

[Allen508]

Just as an old RA1 modder I can say RA1 was more than just different graphics and larger maps.

[Eisengeist]

Different scale for speed.   My old comparisons from racing units: http://xo.cncguild.net/cnc/speed.txt