Drive belt replacement thickness

[Brent]

I know the drive belt is to be replaced at 15,000 miles, but what is the minimum thickness the belt can be before you should replace the belt? I live in a hilly area and I believe my belt is wearing faster than normal. My top speed has fallen from 74mph to 69mph.

[homie]

For your 2015 model... 21.6 mm or (.085 in) take notice of the area measured