I just bought a Powerstroke brand pressure washer with a Subaru EA190V engine. The oil that came with it says 10W30 14 oz bottle. The engine manual that came with this pressure washer says it takes 20oz of 10w30 oil. Why would they include a bottle that is short of the amount required by the engine manufacturer. Glad I checked this so I make sure to add enough but I imagine most people don't pay attention to the amount and just pout it in and fire it up.