2002 156 2.0JTS + oil levels:

We all know that Alfas use oil. When my oil starts to get low I can hear a
difference in the engine noise and in the past I have always topped up the
oil immediately. Only once in 8 years has the computer's oil low message
beeped at me. I stopped within 200 yards and put a litre in on that
occasion.

My question is, how much damage would be done if I keep the oil at a low
level - in other words, wait for the warning and then stick a pint in, then
wait for the warning again and stick another pint in and so on. The reason I
ask is that the performance of the engine improves noticably when the oil is
low and I rather like it!! Clearly the performance is better because the oil
level is low enough to allow 'things' to move more easily as the drag is
reduced, but it is not low enough to warrant a warning, however that lack of
drag means the oil is possible not doing its job properly???

Opinions / facts / advice please...

TIA.