ATLIEN wrote I’ve got a lower utilized m3 with Michelin Pilot 4s that I got new 7 years ago in 2018. I’ve probably put 7500 miles on them during that time so tread depth is great. Experts say that 6 years is time to replace no matter tread depth. Are you low mileage drivers following this rule or pushing it out?
From the Michelin website linked below:
Ten years is a maximum: If the tires haven't been replaced 10 years after their date of manufacture, as a precaution, Michelin recommends replacing them with new tires. Even if they appear to be in usable condition and have not worn down to the tread wear indicator. This applies to spare tires as well."
https://www.michelinman.com/auto/auto-tips-and-advice/tire-buying-guide/when-do-i-need-new-tires
From my own personal experience it really depends upon how the tires have been used and stored. Regarding storage: If the tires have been kept away from ozone (think L.A. atmosphere and nearby electric motors), stored unloaded, away from direct ultra violet, and away from high humidity then tire life is typically enhanced via reduced oxidation and stress.