Realistic 4×4 Traction System V1.4

Realistic 4×4 Traction System V1.4

Multiplayer in development, playable but may contain bugs
Take real control of your tractor’s traction — engage 4×4, lock the differential and let the system react to actual wheel slip, not just to an assigned key.

This mod adds a fully switchable 4×4 traction system to compatible vehicles (tractors, trucks, harvesters, cars): engage/disengage the front axle when needed and toggle a differential lock that trades turning radius for maximum grip in mud, snow or during heavy work.

Features
Real rear-wheel slip detection — automatic modes react to actual wheel-slip physics, not just speed
Four driving modes, assigned to each vehicle by default:
Manual — always in control
Semi-automatic — engages with actual wheel slip, while manual control is always available
Automatic — the same logic, adjusted for vehicles with factory-fitted automatic 4WD (CVT/IVT transmissions)
Intelligent — continuous, proportional engagement in the Fendt style (without abrupt switching on/off)
Native tyre-pressure simulation during engagement — no dependency on any other mod
On-screen HUD with real-time status and adjustable position in the game Settings menu
Zero XML changes to any vehicle — the system integrates automatically into all compatible vehicles

V1.4.0.0
New
– Physical traction prediction (tractors with GPS): compares the required force (slope, rolling resistance, effort from LOWERED implements) with rear axle grip, according to the soil type and ground moisture.
– Front axle engagement by clutch on a ramp (~0.4 s), without jolts.
– Differential lock in 3 positions (Ctrl+K): open / rear / rear + front, with progressive engagement.
– Auto/smart: engages with the implement lowered in the field, when wheels are slipping, downhill with a load and at low speed under load; disengages during tight headland turns and at road speed; remains engaged for at least 6 s (no “flashing on and off”).
– Automatic locks while working; they release when turning, braking or above 15 km/h (in all modes, for safety).
– Maximum speed with 4×4 engaged: 25 km/h (tractors/harvesters), 40 km/h (trucks/cars).
– No mode engages 4×4 above 20 km/h, not even with Ctrl+J.
– Tyre pressure (Fendt) follows field/road conditions, like the real VarioGrip.
– New HUD: live wheel slip, padlocks on locked axles and the REASON for each decision;

Fixed
– The terrain prediction remained high (e.g. 27%) simply because a heavy implement was attached, even when lifted.
– Braking activated 4×4 and the locks (wheel slip while braking no longer counted as a lack of traction).
– Multiplayer: Ctrl+J in automatic modes was undone by the dedicated server.
– Semi-automatic mode never disengages on its own (only the player can do so).