Automobilista 2 Ultimate Modding Guide - UPDATE: How To Custom AI

From here on, our Ultimate Automobilista 2 Modding Guide will make a turn and deal with the aspect of how to actually create mods or at least alter game data. The first area we are going to tackle is the topic of Custom AI.

By using Custom AI files you can inject even more realism and authenticity into Automobilista 2 leading to even more immersion. Because Custom AI files allow the default Reiza driver names, nationalities as well as more than a dozen driving values to be edited and tweaked to your heart's content. You can even set track-specific performances for drivers.

Image credit: Brainbug / IMMERSION Modding Group

Admittedly, most of the skin packs now come with pretty good Custom AI files. So in 95 % of the time you may be good to go and will have an accurate drivers' BoP representation of the corresponding class, series, or season. However, sometimes some fine-tuning of an existing Custom AI may be necessary, because you disagree with the existing values or because you want to create your own for a certain series or event.

For instance, in the 1988 F1 season Nigel Mansell had 12 DNFs in 14 races and generally was inferior in his naturally aspired Williams-Judd to the turbos of McLaren and Ferrari, ending up only in 9th in the drivers championship. However, especially at the season-opener at Jacarepagua, in the rain of Silverstone and on the tight Jerez circuit he was very competitive and able to achieve a 2nd place in each of the latter two Grand Prix.


Thus, to accurately set the Custom AI for that class (F-Classic Gen2), there should be two Mansell entries; the first one with rather slightly above average skills and an abysmal "vehicle reliability" value, and a second track-specific with much better values for Jacarepagua and Jerez (in the picture, Silverstone is not included for it being a race in the wet, for which there is a separate driver's value named "wet_skills").

In our Ultimate Automobilista 2 Modding Guide we will show you how to create and edit a Custom AI.

How to Mod AMS 2 and Create a Custom AI: Tools​

To create and edit an XML file you can either use a text editor such as Windows' "Editor" or "Notepad++".


Or you download and use AMS2 Custom Drivers Utility by LuxMundi. This is an open source Java app that allows users to quickly and easily generate new or edit existing Custom AI grids for Automobilista 2.

Image credit: LuxMundi

File Type and Drive Location​

But let us start with the basics and then do it step by step. All Custom AI are .xml (Extensible Markup Language) files and have to be put in the following folder: UserData\CustomAIDrivers\. This folder is located in your Automobilista 2 steam folder which is usually here C:\Program Files (x86)\Steam\steamapps\common\Automobilista 2\UserData\CustomAIDrivers\.

To make a Custom AI XML work, it has to be named exactly like the vehicle class in AMS 2, e.g. "Group C.xml" (without the quotation marks). Below you will find the full list of vehicle class names in Automobilista 2.

How to Mod AMS 2: Assigning Liveries to Drivers in Custom AI​

For each vehicle class you want to assign AI drivers to, you must create a .xml file. Hence, if, for example, you want to edit the drivers of the Carrera Cup class, you need to create a file named Carrera Cup.xml and put it in your \UserData\CustomAIDrivers\ folder. Tip: Copy an existing file and only edit the changes. Thus you will have the correct syntax from the get-go.

Each driver is assigned to a specific livery, which in the XML is called livery_name. livery_name is the name of the livery as seen in the vehicle selection screen in-game. Hence, In the above example the livery_name "Porsche AG Rothmans #1" is assigned to Jacky Ickx. You can assign drivers to as many liveries as you want.

Creating Driver Personalities​

Apart from name and nationality, there are 15 further parameters for each driver to shape their personality on the track, including race skill, aggression, tyre management, or avoidance of mistakes. As this is the core of a Custom AI, let us have a close look at how that works. Below you will find all skill values and an explanantion of what they do.

How to Mod AMS 2: Values Range and Logic in Custom AI​

When creating a Custom AI and defining values, you should know and note the following:

• The valid personality values range is between 0 and 1 (inclusive). One exception is the vehicle_reliability parameter which is explained further below.
• For even further fine-tuning, you can set up to 3 digits after the dot, like 0.001, 0.537 or 0.999.
• All AI personality parameters are calibrated so that 0.5 is an realistic-ish average driver's value. 1 is mapped to be a realistic-ish high extreme, and 0 is mapped to be realistic-ish low extreme.
• Always test the values of your Custom AI drivers values to see if they are matching the result you would expect, and adjust it accordingly for your custom sets. For instance, when replicating a series like F1 1988, take a look at the real (qualification) lap times of all drivers and then set the (qualification) skills for every driver accordingly to match the real gaps (which were sometimes six or more seconds between the pole-sitter and the last driver on the grid).
• The game always prioritizes Custom AI entries over default values. Thus, if a Custom AI consists of say 26 drivers but you race with a 32-cars grid, all 26 Custom AI drivers will be in there. On the other hand, any missing or invalid values are replaced with the original (default) values of the AI driver that would be picked for that car in that event.

A Strange Beast: Vehicle Reliability​

Vehicle reliability is a special, more complicated beast. To tame it and get it to work, you will need to be aware of the reliability range Reiza has set for each class as well as understand the term "mean minutes". Mean minutes defines the minimum and maximum range between possible failures measured in minutes. Consequently, you will need to do some math to turn it into the final reliability for a driver in the class in question. Maybe time from some spreadsheet acrobatics?

For realistic reliability values, now first gather the minimum (y) and maximum (z) mean minutes between failures for the class you are working on (see above). Then consider your driver/team target mean minutes between failures (x) that you have derived from some real race statistics applying this formula:

sqrt((x-y) / (z-y))

Example: For the F-Classic Gen2 class there is a minimum of 25 mins and maximum of 700 mins. Now if our target for Nigel Mansell is 50 mins between failures, the term will look like this:

(50-25) / (700-25) = 0.037

Thus the vehicle reliability for Mansell is 0.037, which in the Custom AI reads like this:

<vehicle_reliability>0.037</vehicle_reliability>

Alternatively, if you wish to just set a reliability and see what happens, know that values above 0.6 are generally better for each class - relative to how reliable or unreliable the class should be. But for maximum chaos you can of course give low reliabilities a try.

If you wish to go below 0.0 or above 1.0, that can be done too. But know that if you go negative, the formula changes to this:

-((y/x)-1)

Please note that when negative, vehicle reliability is used as a divider for the minimum mean time!

Note that mean minutes between failures is simply a way to quantify reliability. In the end there can be a lot of variance and generally speaking if you want someone to last for 60 minutes consistently, better make them much more reliable than that.

Modding AMS 2 Custom AI: Tips, Limitations and Intricacies​

To round off this chapter of our Ultimate Automobilista 2 Modding Guide, we would like to point out some limitations as well as give you some tips to make your life easier when creating or editing a Custom AI.


An accurate Custom AI is characterized by the fact that it corresponds to reality in absolute terms as well as in terms of relationships and dependencies. Thus, using our above example of the 1988 F1 season, this means that Senna and Prost are generally the fastest and have the most reliable cars. Accordingly, their values for qualification skill, race skill and vehicle reliability should be the highest. At the other end of the scale should be drivers like Bernd Schneider and Piercarlo Ghinzani. While everyone else in between.

General gameplay setting always override specific Custom AI settings.

Tips for creating the perfect Custom AI

• Detailed statistics of real races and seasons are an immense, indispensable help in finding accurate data and values. Search for instance Wikipedia or dedicated motorsports sites for useful data.
• General gameplay settings always override a custom AI. Thus, the selected Opponent Skill Level and the multipliers for for instance tyre wear or fuel comsumption significantly influence the absolute performance level of the AI drivers. We therefore recommend setting the Custom AI so that it delivers the best results with authentic settings and (depending on the class) an opponent skill level between 100 and 110.
• Test, test, test: The best way to do this, of course, is to cover real race distances. However, as this is very time-consuming, there is also the option of pausing the respective session (practice, quali, race) and selecting "Skip to End". This simulates the session. The result may not be as meaningful as if you had driven it in real time, but it still gives you a good indication of the general pace, failure rates, etc.
• The difference in pace between qualifying and the race is smaller with the AI in AMS 2 than in reality. Caution is therefore advised, especially in the historic classes, as the AI is almost as fast with a full tank of fuel as it was before in an almost empty car, while the player has to contend with all the disadvantages of a heavier car and cold tires. This can be a fun killer, especially in time-accelerated races. To remedy this, you could set the race skill for all drivers slightly lower by for instance 0.2 or 0.3.

Further Helpful Resources​

• Modding Automobilista 2 Is Easier Than You Might Think
• Top 10 Most Popular Automobilista 2 Mods
• Automobilista 2’s Top Tin Top Liveries
• Automobilista 2 | The Ultimate Formula 1 Season Guide
• Automobilista 2 DLC Guide