We're all overlooking the "elephant in the room"... If it's a Quantum engine, it's not meant for you to change the oil. If you RTFM, it will probably tell you to just check the oil, and add as necessary. The ( useless ) theory being that as the motor wears, and starts to use oil, the oil that you add will supply the necessary additives for the engine. Briggs assumes that the rest of the product will be done before the engine grenades from the worn out oil. Planned obsolescence, and, a marketing ploy.. Never needs an oil change!!