I currently have 110k miles on the car and have never had it done. Tires are wearing normally/evenly and rotate them often. No one has suggested I replace them: not Toyota, my mechanic, tire dealer or my alignment guy. When should I do the replacement?
when the ride becomes uncomfortable, you have a leak, or the tires become a problem. a preemptive strike isn't a bad ideaeither, if you're keeping the car long term, but not necessary
I recently replaced my springs and shocks on my PIP. It rides a little higher but I no longer scrape the front and the car handles like an f1 race car.
I currently have 93,000 on my 2013. Absolutely love this vehicle. If there is one item I am not happy with it is the shock absorbers. With the current state of roads in N.J. there are a lot of pot holes. Occasionally when hitting a pot hole it seems to "feel like a direct hit." I guess I need to watch more carefully and avoid pot holes! My prior Prius was a 2005 and when I sold it at 129,900 miles it seemed to have a better ride suspension/shock absorbers. Hope everyone is well, safe and Happy New Years!
you should also replace your springs while you are in there. check out some of my blog articles regarding Toyota Prius springs