I'm kinda new to these 'belt tensioners'.
I looked at mine and thought:
There's a bearing in there, how many times does that bearing turn with each turn of the belt ? ? ? Answer: Quite a lot.
So I changed mine at 92,000 miles.
My Rule for replacing parts-
1) Buy Equal or Greater Quality.
2) If the part I'm taking off (OEM) doesn't show any wear, save it.
Might come in handy in emergency.
Should you change yours ? ? ? Depends on mileage.
Do bearings feel smooth ? Making any noise ?
The belt your taking off, if it has any life left, keep it in your vehicle.
A few years ago, I took my truck to get rust proofing (oil spray) done.
The owner came in and said "your drive belt just broke".
How many people can say "I have one hanging behind the drivers seat, with breaker bar & socket".
Edit: That's a true story. No brag, just fact.