[RKDinOKC]

When I describe and oil as getting watery, if measured at the proper temps have usually not lost any actual viscosity. However it seems thinner on the dipstick and when drained. On the 951 and 928 this also shows as lower oil pressures at idle when up to temp. With a good oil when fresh warmed idle pressure is around 3 barr. As the oil thins, ages, gets contaminated, or gets "watery" the warmed idle pressure is closer to 2 barr.

Most oils, after 3 or 4 autocross laps, drop down below 2 barr and sometimea low enough the low oil pressure light comes on. Turning the car off and letting it cool for 10 minutes or so usually brings it back up to just above 2 barr, or reving up a couple hundred rpm off idle does the same. Saw this on both my 951 and 928. I always took it as a sign to change the oil.