I am thinking exactly the same. It's actually a new kind of motivation to deliver a decent statistic.
I my current patrol, I have reached my personal record in torpedoe efficiency. Manual targeting of course, and no reloading.
Sunk 1 Victory, 1 T3, and 2 NOTSf with a total of ~25,000 tons. Fired were 11 Torpedos(9 hits, 2 misses and zero duds). This makes average per torpedo 2272 tons, which I find extremely high for my rather average skills
I played together with a friend, and we were discussing tactics and solutions, which is kind of cool. We were always getting in a perfect position ahead of the target, and firing at 500-1000m, so that accounts for the great results, and a stroke of good luck of course.