Couple of things will destroy a tire, and yet it will look good on the outside.
1) Running underinflated. This causes the tread package to "unglue" from the tire carcass, due to excessive heat, and fail even though the tire still looks good.
2) Age. Check your date codes!
3) Sitting flat for long periods. weight of the vehicle permanently deforms the steel belts, and or damages the casing. Tire will air up and hold air, but vibrate. Balancing will not fix.(think A2 trucks with CTIS inop)
4) Flat repair/external tread block damage. Damage to the exterior or flat repair allow a path for moisture to enter the tire causing permeation.
5) Thin tread. Tread acts an insulator from the road. The thinner the tread, the more heat gets absorbed into the tire during operation.
6) Permeation. Due to the above causes listed and/or use abuse(overload, overspeed, underinflation) Inside of a tire is a thin rubber liner. It seals the tire, keeps moisture out of the steel belts, and generally holds the psi at a constant pressure. When it starts to fail, whether old or new, it is hard to detect. If you get a new tire, and you can't keep psi consistent, then it is most likely the failure of the inner rubber liner. Moisture will then get in between the carcass and the tread package, and air pressure will aide in separating the 2 components. If a new tire won't stay aired up properly, GET RID OF IT!
I had major issues with a bfg mud terrain tires on my superduty. Had 3 new tires blow out in less than 250 miles. They were bought new, properly inflated, and not abused. Insurance said it was a manf. defect so no help. The root cause was BFG didn't put any glue on the casing to the tread package.
So beware when messing with tires. If you get a vibration, have it balanced. If it continues to vibrate, get rid of it. If you have one that looks new but won't stay aired up, get rid of it. It's cheap life insurance for both you and the other people on the road around you.