In a giant crossover/SUV/van, with separate front and rear climate controls, do I need to run both, when no one's back there?
My new(er) vehicle is a large crossover type of thing. It allows me to run AC front and back, or just in the front. I figured I wouldn't use it, when there's no one back there. But then, if I'm only running the front, isn't it conditioning all of the air in the cabin, anyhow? So I've taken to running front and rear when it's been sitting out in the heat for a while, and then cutting off the rear AC once we're underway, and things are cooled down. But when things get into the 90s, or above, having both of them feels a lot better.
When there are passengers in the rear seats, it's a no-brainer, but should I expect to have to run both front and rear most of the time?
The owner's manual is no help, so