Car tires last too long
So I just had to buy new tires for 'my' car (our 2nd car), turns out last time I bought tires for that car was late 2010, so they lasted almost 9 years. 7 of those years I have been 90+% bike-commuting, so total miles was only around 50,000. There was plenty of tread left though, they died of old age (drying, cracking, splitting).
So for these new tires, since they will include 0 years of car-commuting, 50,000 miles would be like 20 years. Is it possible to care for the rubber to make the tires last as long as absolutely possible?
Note this is SoCal, so the biggest hazard is probably sunlight. I can't imagine 100-degree heat does much to car tires, compared to how the temps they reach while driving. The car's parking spot (when I have it at home and not in the parking deck at work) has the car facing east, so the passenger-side tires get all the sun. Maybe I should saw up some plywood light shields for those two tires?
Would any of those tire beautification sprays do any useful conditioning? Or is that just for cleaning and shine?