Per Carlisle our oldest ST tire maker;
Time and the elements weaken a trailer tire.
– 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 cases.
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I ran the first two sets of 16" LT E BFG Commercials for 55k and 52k miles and 7 and 8 years of service on my 11200 lb trailer. Both sets were getting close to the tread wear bars so I sold them to guys with lawn service trailers.
All my trailers sit in the tractor barn or trailer shed.
The sun ruineth all.