I have put 1200 miles on my car in the past four months. I know the oil is still good but I checked the dipstick yesterday. I'm down 1/3 quart. Should I add more oil to bring up the dipstick to full or should I let it burn till the low level of the dipstick then drain the oil for oil analysis? I know if I add oil, it will dilute the batch I have in there now. Since this is my first oil analysis, I want to know how much silicon I have in there since I put a KN air filter last year. opinions?