How old is too old? I have a 2009 Challenger with 9,200mi. At this rate they would be 20yrs old before I wear them out. I think the manufactures say 6yrs but they want to sell tires.

My 1st car (mid 70's) was a 49 Plymouth. My dad found a set of original tires for it that had the tar paper wrap on them. I drove on those for yrs but it wouldn't go much over 50mph.

They say 6 years so some moron doesn't drive around on 20+ year old "new" tires, have a blow out, kill themselves and then the tire company gets sued.

That's why they say 6 years.

My personal opinion is that there are lot of factors that go into that decision. It is absolutely not a 'one age fits all' kind of thing.

We use new spare tires from the salvage yards on our trailers. They are cheap since there will only be one of any given model. And some of them are 15 years old, maybe older. But with no sun on them, they look as good as new and I have no more problems with them than any other tires.

Then there are some of the cheaper brands of tires that I see with lots of weather cracking on the sidewalls after 4 or 5 years.

One other factor that may or may not matter here is traction. As all tires age, they get harder. So, while blow-outs might not be a problem, skidding might.

Remember Paul Walker? They believe that the age of the low mileage tires on the Porsche played a significant role in that crash by loosing traction due to hardening.

So, when to change your tires depends on your particular circumstances.

"Back in the day", tires did not last long in miles and had more limited traction. Today, tires work better... and also seem to age faster. "Dry Rot" happens faster.

As mentioned, it is a personal choice what to do. If I were driving the car, I would replace the tires after 7 years.

The tires on my Charger were 13 years old but looked great. I replaced them only because of age. They were 50% tread in the rear and around 80% up front.
Today the Wife had a blowout in her spare car. We rarely use it now except to cart the dogs somewhere. I looked at the date code......2006 ! What???
On close inspection, there are all sorts of tiny cracks everywhere. Good thing she wasn't moving fast.

Comes up all the time. Here: https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2369374/1.html

From my experience with truck tires at work and personally, I'd say 10 years in there approx life span.

Recently wife drove our durango to Montana 4000 miles round trip on 9 year old tires that had 48K miles on them with about 3/8 thread left. 80mph out there for hours at a time...

She made it out there fine. Checked the oil and air in all four tires before she left MT to come home and made it to Iowa and had the sidewall blow out on her right front. Luckily it happened as she was getting on the highway in the morning as she was leaving the motel. She had a spare on board and we were able to get a road service guy from the area to change it for her on the side of the highway. Tire guy told her the tires were old and that is more likely why it blew.

Police showed up too behind her with his lights on, thank you police for that.

She is not dumb about air pressure as she watched me for years check trailer tires. She checks them each time she walks around the car with her eyes had a tire gauge in the consol she used in MT. her tire was not low, the sidewall gave out from either wear or she hit something on the highway. She says she did not hit anything that she knows of.

I mounted her Goodyears in 2010 that I got from the Tire Rack. The date on the tire is the 42 week of 2008 they were built. They do show some cracking in the sidewall, they are toast at 9 years old.