Originally Posted by oledoc2u

there is still only 1 way I know of to know the quality of oil, and that is an oil analysis by a lab equipped to do so. This device can't do that. It has set parameters to quess how long you should go, but no real way to know what the quality of the oil is. You could put used oil in there, based on the vescosity of the used oil, this would be determined by the heat build up, I would assume, it would give you an approximate time to change your oil. But it is still used oil. Just change it at an interval you are confortable with, but I won't believe this sensor crap...sry...no real way to know for sure what the break down of the oil is...