The non power producing half is not decoupled, so it does consume power from the running half. It is simply that other than common crankshaft and gearbox, no part of the engine depends upon the other half to continue running. The remaining 43% power with one half shut down was enough for even a gentle climb if needed. The older Cadillac system did actually hold open valves to decouple certain cylinders for efficiency, but that involved yet another "system". I'm very content with the duality which RED has designed in, it does what [hopefully you don't] need, better than any other single engine!