Set to roughly 20%–30% to avoid unrealistically short stopping distances.
Are you planning to use this mod with a or a steering wheel setup?
Reviews for these mods often highlight a divide between "difficulty" and "realism":
To get the most out of these mods on version 1.41, community members frequently suggest tweaking in-game sliders:
Many 1.41 physics mods refine braking to be less "on/off," requiring more distance to stop a heavy load. Weight transfer is also more realistic, affecting traction and stability during maneuvers. User Sentiment and "Realism"