When to replace a 'serpentine belt'?

[N3FOL]

Is it after 30K or after 60K? Thank you in advance.

 

[sdpatt]

The scheduled replacement of the serpentine belts for the 3.0L is every 60,000 miles and for the single serpentine belt for the 3.2L is every 100,000 miles, both in conjunction with the scheduled timing belt change. The superior constant load tensioners on the 3.2L engine account for the longer change interval for the serpentine and timing belts.