What is the Light Purple M on the HUD for?

[OxyGenIII]

Anyone know what this M represents on the HUD in the new Forza Motorsport?

[Ti_Hsien]

Is it indicating that you have it set to Manual, perhaps?

[FennecTailz]

Race tires, Medium compound.

Other options are:

• S, Soft
• M, Medium
• H, Hard
• W, Wet

[OxyGenIII]

Thank you!