After many conversations about twins and their overpowered engines, I was wondering if in the case of inflight shutdown, what % of engine thrust is required to keep the aircraft at altitude. I am not talking having to maintain speeds of 500 knots, just to maintain altitude. I am also not talking about failures on take off, just for example a mid flight shutdown. We often hear of the added strain on an engine when it is the only one active engine. But if the goal is just maintaining altitude as opposed to altitude and speed, then is this still the case. I am aware that you would want to land asap, but if landing was not an option.
Take the 777 / 767 / 757 / a330 for example, could one engine keep the plane in the air at 30 %, 50%, 80% thrust ?.