Changelog
V1.0.0.2
- Fixed universal DEF support for compatible non-motorized liquid trailers.
- Corrected the vehicle specialization registration so DEF support is applied properly when the game loads.
- Compatible liquid carriers that already support Water, Milk, or Diesel can now also accept DEF.
- Verified working with the base-game ABI 550 Water Trailer.
- Existing DEF vehicle support, HUD, refill system, containers, and store integration remain unchanged.
- No pricing changes in this update.

Description
The Diesel Exhaust Fluid System expands Farming Simulator 25’s existing native DEF functionality into a complete, usable system for properly configured diesel vehicles. Instead of DEF remaining mostly in the background, compatible vehicles can now actively use, monitor, transport, and refill Diesel Exhaust Fluid while you work.

The mod is built around Farming Simulator 25’s native DEF fill type and consumer system, allowing supported vehicles to retain the game’s underlying DEF mechanics while adding the features needed to make DEF a meaningful part of vehicle operation.

Features
- Native FS25 DEF consumer support
- Automatic compatible vehicle detection
- Dedicated DEF HUD gauge
- Independent diesel and DEF tanks
- Native DEF consumption and separate refilling
- Included DEF Supplies: 10 L DEF Jug, 280 L DEF Pallet, and 1,000 L DEF IBC Tote
- Dynamic mounting and tension-belt support where applicable
- DEF transport support for compatible liquid carriers
- Clean store integration
- English and German localization
- Optimized models and textures
- Multiplayer supported

Vehicle Compatibility
Vehicles must be correctly configured with Farming Simulator 25’s native DEF fill type and DEF consumer system in order to use the vehicle-side DEF features. A compatible diesel vehicle should contain its own DEF fill unit and native DEF consumer. Vehicles without a DEF consumer will continue to operate normally and will not display the DEF gauge.

Tested
The release build has been tested for DEF vehicle detection, native consumption, HUD display, independent levels, emptying, refilling, container interaction, store integration, liquid-carrier support, and savegame loading. The final release build also passed GIANTS Farming Simulator 25 TestRunner 0.9.19 with all 14 test modules passing.

Credits
JerseyShoreModding