How to Change Trailer Capacity or Tractor Speed in FS 25 (XML Editing)

Often a great mod has one annoying drawback: a combine harvester with a too small tank, a tractor that's too slow, or a trailer that holds only 10 tons when it looks like it should hold 40. The good news is that you can fix this yourself — just edit a few parameters in the mod's XML files.

In this article, we'll go step by step through how to change tractor speed or trailer capacity in Farming Simulator 25 without complex programs or unnecessary hassle.

Important: Before making any changes, always make a backup copy of the original mod's .zip archive. This will save you if something goes wrong.

Preparation: Creating a Workspace

To avoid getting confused with files, it's best to organize everything properly right away.

Create a folder on your desktop:

FS25_Mod_Editor

Inside it, create three more folders:

  • 1_Original_Mod_Files — for original mod ZIP archives;
  • 2_Mod_XML_Editor_Files — for unpacked and edited files;
  • 3_Output_New_Mod — for the finished modified mods.

This structure will help you keep everything under control and avoid a mess of files.

Part 1: How to Change Tractor Speed in FS 25

Step 1: Preparation and Unpacking

Copy the tractor mod's ZIP file into the 1_Original_Mod_Files folder. Then unpack the archive into the 2_Mod_XML_Editor_Files folder using WinRAR, 7-Zip, or the standard Windows archiver.

Step 2: Find the Main XML File

In the unpacked mod folder, find the main XML file for the vehicle. Most often it's named after the tractor itself, for example:

  • Fendt900.xml
  • JohnDeere8R.xml
  • CaseMagnum.xml

Don't confuse it with the modDesc.xml file, because modDesc.xml only contains the mod description, not the machine's technical parameters.

Step 3: Open the XML File in an Editor

Open the found XML file in a text editor. It's most convenient to use Notepad++, as it makes it easier to search for the needed lines and edit the code.

Press Ctrl + F and find the section:

<motorized>

Inside it, there are usually speed parameters:

<motorized>
    <motorConfigurations>
        <motorConfiguration name="Standard" hp="300">
            <maxForwardSpeed>50</maxForwardSpeed>
            <maxBackwardSpeed>15</maxBackwardSpeed>
        </motorConfiguration>
    </motorConfigurations>
</motorized>

Step 4: Change the Speed

To make the tractor go faster, change the value in the line:

<maxForwardSpeed>50</maxForwardSpeed>

For example, you can set:

<maxForwardSpeed>65</maxForwardSpeed>

You can also change the reverse speed by editing:

<maxBackwardSpeed>15</maxBackwardSpeed>

But don't set too high values, like 150 or 200, because then the vehicle will behave unnaturally, and the game's physics might just "go to another field."

After making changes, save the file.

Part 2: How to Change Trailer Capacity in FS 25

Step 1: Preparation is the Same

The principle is the same: copy the trailer mod's ZIP file into the 1_Original_Mod_Files folder, then unpack it into 2_Mod_XML_Editor_Files.

Step 2: Find the Trailer's XML File

In the folder with the files, find the XML that corresponds to the trailer. For example:

  • KrampeSKS.xml
  • FlieglTrailer.xml
  • KroneTX.xml

Open this file in a text editor.

Step 3: Find the fillUnit Section

Press Ctrl + F and find:

<fillUnit>

Or directly the parameter:

capacity=

Usually the needed block looks something like this:

<fillUnit>
    <fillUnitConfigurations>
        <fillUnitConfiguration>
            <fillUnits>
                <fillUnit unitTextOverride="$l10n_unit_literShort" fillTypes="bulk" capacity="25000">
                </fillUnit>
            </fillUnits>
        </fillUnitConfiguration>
    </fillUnitConfigurations>
</fillUnit>

Step 4: Change the Capacity

The capacity parameter determines the trailer's volume. If it says:

capacity="25000"

that means the trailer holds 25,000 liters.

To increase the capacity, simply change the value, for example:

capacity="40000"

Now the trailer will hold 40,000 liters.

If the mod has multiple body configurations — small, medium, large — then you need to change the capacity in each configuration separately.

After that, save the XML file.

Part 3: How to Properly Repack the Mod

Step 1: Create a New ZIP Archive

Go to the 2_Mod_XML_Editor_Files folder, where all the unpacked mod files are located.

Important: you need to select all files and folders inside, not the outer folder itself. Then right-click and choose "Add to archive...".

Archive settings:

  • Archive format: ZIP
  • Compression method: Normal or Store

Name the archive so you can easily recognize it, for example:

  • Fendt900_edit.zip
  • KrampeSKS_custom.zip

Move the finished archive to the 3_Output_New_Mod folder.

Step 2: Install the Mod in the Game

Copy the new ZIP file to the standard mods folder:

Documents/My Games/FarmingSimulator2025/mods

Then launch the game, activate the mod in the list, and check the result in the shop or directly in the field.

Useful Tips to Avoid Breaking the Mod

  • Always keep a backup copy of the original ZIP file.
  • Edit values gradually, not "by eye" to ten times larger.
  • Don't change random lines if you don't understand their purpose.
  • After each edit, test the mod in the game.
  • If the mod stops appearing in the game, most likely there's an error in the XML or the archive was packed incorrectly.

Summary

Editing XML in Farming Simulator 25 is one of the simplest ways to customize a mod to your liking. You can increase tractor speed, raise trailer capacity, change vehicle characteristics, and make the game more comfortable for your playstyle.

The main thing is to work carefully, make backups, and not rush. As they say, measure twice, cut once — or save the XML once.

Now you know how to change mod parameters in FS 25 yourself without any magic or complex programs.

Want more? Next, I can prepare another useful article for the site:

  • How to properly read log.txt in FS 25 and find conflicting mods