Now that the weather has cooled down a bit (13 C or so vs 20C or so in the morning) my 1990 740 16 valve stick seems to be peppier on take-off than before. Less of a tendency to bog. Ok, I know that cooler, more denser air translates to more power but I never noticed this before. The engine OBD reads 1-1-1, no air leaks that I know of, relatively new plugs and wires, air filter is clean, relatively new fuel filter and so on. Last month I tried a tank of high test to see if it made any difference (no, it didn't) and I had just refilled with regular a few days before the temperature dropped. Could that be it? It seems to me that I should not see a noticable difference in performance going from summer to fall temperatures. I am surmising that the computer is getting the settings closer to optimum now than before. By why? O2 sensor starting to go? Small air leak that closes up in cooler weather? Stuck air intake flap? Alignment of the planets? Clutching at straws here.

I just redid the front brakes and found a calipre pin frozen but there was no sign of dragging brakes.

Suggestions?

Bill