[ESully]

I had noise issues with my Santa Fe. I found a bad ball joint and replaced it. Still had noise and found while the tires looked good, the ball joint had caused the tires to be slightly off. I hated to do it since the tread was good, but had to replace all 4 tires to get a good ride again.

 

[ESully]

I'm only doing about 7K miles a year on the SX and maybe 2500 on the truck. What I run into is tire 'dry rot' beginning around 5 years. The 2007 truck is on its third set of tires at 33K! I never had this problem before I retired - tires lasting 5 years was a dream. It was more like three years, and I put 60K on my '76 Trans Am in two years.

Since I retired I'm having the same "problem". The tires on my Corolla still have a lot of tread, but they will be 7 years old this year and that is the maximum tire manufacturers recommend.
As far as the sidewall cracking, according to Goodyear leo42.2875 has a point.

1. Excessive exposure to ultraviolet (UV) rays from sunlight
2. Low inflation pressure in the tires
3. Storing tires at extremely high temperatures
4. Not using the tires due to lengthy storage of a vehicle or the tires themselves
5. Storing tires near electric motors, battery chargers, generators, welding equipment, or other ozone-generating sources