Focus MK4 change tire size?

[tts]

as title
how to change Focus MK4 tire size to make speed same with real speed?

thx

[Artist]

No one in the world has ever been able to adapt to the speed of a tire.
It's all about correction in Ipc. I don't have fofo4, so I don't know if it's possible ... Almost all are set 5% less.

[tts]

we can do that at FF3
tire size no longer need to be the same as the standard

now i buy new FF4，not found setting yet.