I think it was mentioned earlier about the safety regulations or tire companies not touching tires older than 5-7 years, thats more for liability concerns than actual age. Kind of like how some say braided hose needs to be replaced after 5 years, i have & know of lots of cars with braided hose thats 10+ years old that still works fine with no fuel seepage or leaks. Or the 3000 mile oil change, very rarely does oil go "bad" after just 3000 miles in a healthy engine, the oil companies want you to buy more oil. Lots of things do that, home washer hose replaced in 3-5 years? There are millions of houses with 10-15+ year old washer hose. yes anything can happen but just like lots of things, the odds are very low that any item will fail when the manufacturer or safety people say they will.
I have tires on some of my cars that are 10 years old but look great with no signs of cracking, belt slippage etc, they all get stored for 4-6 months a year in winter & never have flat spots, usually BFG T/A or firestone indy 500.... but then again I dont daily drive these cars & rarely if ever spend any real time on the interstate at 70+ mph, they are city drivers or back country roads. If i planned a long trip or drag strip use they would get changed or use different tires dedicated for the purpose.
However, the reality is that there are millions of tires that are easily 6-8-10+ years old on the road and catastrophic tire failures are very rare statistically speaking. While I agree its good advice & you should definitely inspect or monitor your tires when they get that old, but its not an automatic thing to change tires if they have decent tread & in good condition after 5 years. If anyone is doing that on 60+% tread 5 year old BFG's or other name brand tires, I will take them & pay for shipping. Lots of burnouts left in them.
