@Cerberus
@1004ron
Thanks for the input.
I asked because although I do understand the concept for replacing it as a preemptive maintenance, but then using the same concept you'd replace so many other parts. Unless a specific part is known to fail, or cause a disaster if failed (internal water pump).
Also, searching around for Ford tensioners, found this on Motorcraft, stating they are tested for a 10 year / 150k mile life cycle.