Realistic 4×4 Traction System v1.0 fs25-mods

Description:

A dream that's been years in the making. I'm a long-haul truck driver. Farming Simulator has been my escape between routes for as long as I can remember — but there was always one thing that bugged me since the very first version I played: the 4×4 system never felt real. It was always just an on/off switch, if it existed at all. No real differential behavior, no automatic engagement, nothing like what actually happens under a tractor when the wheels start losing grip. I never had the time to do anything about it — until now. Every scrap of free time I get at home between long trips, for the last several months, went into this mod: reverse-engineering how the game’s physics actually work, learning FS25 modding from scratch, testing, breaking things, testing again. I used AI assistance throughout — to study the game’s internals, learn the scripting, and help write and debug the code — and I want to be upfront about that, because I think it’s fair to say so. This is the result: a 4×4 system built on real differential physics, not a cosmetic toggle. **What it brings:** - Real differential physics — front axle engagement and differential lock act directly on the vehicle’s physics, not a cosmetic effect. - Four traction modes, assigned per tractor based on real-world transmission type: - Manual — you decide when to engage - Semi-automatic — engages on its own when it detects real rear wheel slip, with manual override available - Automatic — same principle, for tractors with “classic” automatic systems - Smart (Fendt VarioDrive) — gradual, continuous engagement proportional to slip intensity, no fixed ratio, just like the real system - Real slip detection — not just speed-based: the mod reads actual wheel slip to decide when 4×4 should kick in. - Optional synergy with Variable Tire Pressure — if installed, tire pressure automatically adjusts between field/road mode as the 4×4 engages or disengages. - In-game adjustable HUD — reposition the indicator right from the game’s General Settings menu, no file editing required. - Restricted to tractors, trucks, harvesters and cars — stays out of trailers, implements, forklifts, and anything else where it doesn’t belong. - Requirements: Single-player only for now (no multiplayer server sync yet). - Credits: The differential manipulation technique was confirmed through reverse-engineering FS25_EnhancedVehicle; the tire pressure synergy uses Variable Tire Pressure’s public API. No third-party code was copied — only the techniques were studied and reimplemented from scratch. This is a first public release, built by someone who’s wanted this to exist for years and finally found the time to make it happen. Feedback is very welcome — if something doesn’t behave right on your tractor, tell me which one and I’ll get it sorted. **Changelog** - v1.0.0 — Initial release - 4×4 traction system based on real differential manipulation (not cosmetic) - Functional per-axle differential lock - 4 configurable traction modes per vehicle: manual, semi-automatic, automatic, smart (Fendt) - Automatic engagement based on real rear wheel slip detection, with hysteresis and confirmation delay - Smart mode: gradual, continuous engagement proportional to slip, automatic disengagement above road speed - Optional synergy with Variable Tire Pressure (automatic field/road adjustment) - On-screen HUD showing 4×4/2×4 state, traction mode, and differential lock status - HUD position adjustable from the game’s General Settings menu - Automatically restricted to tractors, trucks, harvesters and cars - Initial support for major tractor brands (see DriveModeConfig.lua for the full list)