water usage

Are you certain there is no leak? Have a pressure test done on your cooling system. This will say for sure if it holds pressure. If it does hold static pressure, and there is unexplained coolant loss, it may be getting ingested through leaking head gaskets or cylinder head cracks.

could be your rear main seal leaking int to the engine or thermastat going out causing it to spray off while driving then cooling down enough not to show a leak