"I recent read an article somewhere that warned about using tires that were more than 5 years old no matter how good they look."
That's one of the problems inherent with capitalism. Built in obsolesence is encouraged because it is profitable. That is why we are a wasteful throwaway society.

The "superior" materials used in the product too often have a limited lifespan. I bought a pair of Terra Lite work boots. Nice, light, comfortable. Barely used them, put them away. A few years later took them out for some heavy work. While doing some heavy moving felt something on the sole. Checked and found that the soles were cracking and crumbling. Complained to Terra Lite. Shrug. They didn't design them to last. Just be light and comfy. So my new boots are the old heavier sole kind. (Hated to throw the TerraLites out because the uppers remained in great, comfy shape.)

I know kinda off topic, but it bugs me that they are urging us to replace our tires more often even though they don't know what to do with the old ones (other than have bonfires in tire dumps). And I wanted to vent.
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1980 245 Canadian B21A with SU carb and M46 trans in Brampton, Ont.