The procedure to check the oil is to run the engine for a couple of minutes then shut down the engine and check the oil with the dipstick. This makes sense because it allows the oil to fill the oil tank that the dip stick is located in. After shutting down the engine, the oil all apparently drains down into the engine case. If this is the case then it seems that the amount of time between shutting the engine down and taking the dipstick reading would have an effect on the measurement. (The more time that elapses, the more oil will be in the case and not showing up on the dipstick). I haven't had any trouble getting an accurate oil level reading and maybe I'm being a little annal, but after thinking about it, I am wondering just how this oil system works. It seems that if oil is constantly draining down into the case after shutdown, it would effect what you see on the stick. For example, after sitting in the garage overnight the dipstick shows absolutely nothing on the dipstick. Anyone care to shed some light on this one?