I guess it is safe to say that checking the oil with the dipstick is still the best way. I feel the computer does a great job telling you if you have to add oil, but I believe, and will, use the dipstick to see exactly where I am. When I bring my car in for my first service I am going to ask the shop manager about this. As I stated before, a one quart difference to me is significant. How do you all feel. How many use the dipstick in addition to the computer?