we have 2 kinds of wheel support on PS4, Legecy mode support and Expert mode support,
In legecy mode, your G27 will be recognized as a controller, so most of the games can accept it.
you can add an NFS19's config to play your Mudrunner.
In expert mode, your G27 will work as a Logitech G29, which can be recognized by the console.
but you will need to make sure Mudrunner can accept Logitech G29 on PS4,
for we use similar communications.
To try this, you can add an Expert Mode's config to play Mudrunner,
if your game can recognize G29, then you can play in this mode.
