Wow.

I didn't know that IC manufacturers make separate chips in regular grade, car industry grade and military grade.

From what I can see from the specs, the latter two tolerate more variation in operating temperature, acceleration/vibration, and choppy voltage/current.

I wonder if they always aim at producing military grade, test each batch randomly, and then dump the lowest quality batches to regular use.

It would mean that by buying regular, you can end up having a military grade chip.