Forza games always have proper tire and car physics, setup and telemetrie... Even drivetrain elasticity is properly simulated in Forza games... Thats why it has the Forza title in its name and not Need for Speed Horizon or The Crew Horizon... It was the idea from the start of the Horizon series to bring the Forza physics in an open world
If someone wants to be know more about how things in Forza work look here:
https://www.twitch.tv/forzamotorsport/v/15359698
1:46:00: Laserscan Tracks, also at 7:23:00, Updates of IRL changes to tracks
1:55:00 Licensing Track, Cars
5:24:45 How to make a Forza Game mit Creative Director Bill Giese
6:10:00 Audio and Music Q&A mit Audio Director Nick Wiswell
6:18:00 Drivetrain Elasticity, Sound Engine
8:18:00 Physics, Tires, Older Cars
8:29:40 Rain/Wet Tracks
8:31:55 Puddles