Tire chemistry is complex, but in a nutshell, tires contain UV
protectants, mainly carbon black (which is why tires are black), and
anti-ozonants, mainly hydrocarbon waxes. Ozone, a form of oxygen, is
the great enemy of tires. UV speeds up oxidation/ozonification. So
keep your tires out of the sun if possible. Petroleum distillates
dissolve hydrocarbon waxes and are bad for your tires. Most tire
dressings contain petroleum distillates and should not be used,
especially if you live in a big city swimming in ozone. Michelin, I
believe, makes a tire dressing that not only does not contain
petroleum distillates, but contains UV and anti-ozone protectants.
Not sure about Armor-All but I think it has some kind of UV
But having said all that, the treads will probably wear out before
ozone ruins your tires.