Some interesting info from
Carlisle web site.–Maintain air pressure at the maximum PSI recommended on the tire sidewall. As opposed to a load chart most tire companies refer to as I noted above.
And;
–3 to 5 years is the average life expectancy of a trailer tire, regardless of mileage.
– It is estimated that in approximately three years, roughly one-third of a tire's strength is gone.
– After three years, depending upon storage and conditions of usage, consider replacing trailer tires even if they have tread depth remaining.
–After five years, trailer tires should be replaced in all casesSeems like pretty low numbers.