That is correct based on our hybrid. Per my other posts ours was charging going up Loveland Pass in some sections where the grade let off. Hybrids do just fine on long mountain passes. The ECU is constantly switching between electric charging and assust, including charging from engine or wheels, and the while process is imperceptible.I get what you're saying, but wouldn't the 4cyl charge the battery while you're running up the hill? In theory, the battery will never run out of juice, even on the highway because the ICE will charge it up.
Toyota hybrids are A+++. Jury is out on one in a 4x4 but I'd have a hard time getting anything else for a daily.