Stacked?
Couple yrs back I got a set of regular 16" Mich radial tires from Sears for my wifes Infiniti

.
To my shock on my first test drive that car rode worse than one that had been sitting in one spot for a decade (been there too) and the car actually wobbled like hell at low speeds.
I returned and when rechecked, 3 out of 4 would not balance right. They ordered me another 3 and it was smooth as glass until about 60mph then a slight shimmy came in.
Again I returned wanting that 4th tire. He asked me to drive it a few days and he'd order it in, said to try to drive long enough to heat up the tires real good and see if its problem went away?
Wife & I took a 125 mile round trip the next day and these tires have been flawless since. Never worried about the 4th one again.
I was told they were stacked too high/wrong at the warehouse for a long period and the weight created belt issues.
Regardless they are by far the best radial tires I ever had on anything and Ive owned over 130 vehicles. Smoooth at all speeds!
Alot of things happen from production, materials,storing & shipping & shipping again & probably again can create issues like this. Knowing what I know now I would have another set ordered before I bailed first round..
But not knowing or being told I'd sure think they were just crap tires too. :doh:
Sorry long post, my story though. Hope it helps someone later!