Manual Oil Analysis. I know just about everyone here must do it. Pull the dipstick out and check the color of that drop of oil still hanging on the end of the dipstick. -- or how dark it looks on the crosshatches. Then, put that drop of oil on the forefinger, and rub it lightly between your thumb/forefinger to check for lubricity. In the old days (70/80’s) with the old Grp I based oils, it seemed like one could tell that after a 3000mile/6month oil change that the oil was loosing its lubricity. These, days, no matter how long I go the oils still feel really slippery even when drained at the end of my OCI.