<p>Based on this and your previous posts, you do seem to have a knack of knowing the hardest working but least successful engineering students. From what I saw, 80+ hour weeks were very unusual, only occasionally seen for those in project courses when projects were close to the due date (and not every student in such courses; those who managed their time well and did not procrastinate kept the weekly hours reasonable even as projects came due). And that was years ago when (according to the paper linked above) average number of hours per week was higher for various reasons.</p>