Tire Life.. Old tires Low miles

[Project_Gotham]

I have had my Nitto Invos on my car for 7 years and I'm finally starting to drive the car. I have only put about 500 miles on them and I had a blowout yesterday. I think the tire was low causing the blowout.

The tires look good, no dry rot, seem soft and sticky...

My question.... Are these low mile tires too old? I will compare with the new tire when I get it mounted. Thoughts???