Still, that is better than demanding 68 out of car AC in the hot sun. My auto AC runs very smoothly, but I am beginning to think that such function is, indeed, affected by your starting humidity. Humidity is usually extremely low in New Mexico, where I am. And I have never seen the unit confuse the need for cooling with heating. Do not know why altitude might affect it, but even our river basins are above 4400 ft. Maybe some combo of low humidity and altitude. Someone may have a scientific idea about this.I don't have much of a choice here: I have to leave mine on 73 auto. If I set it on 76 auto, it'll command heat even when it's 85-87F outside! Only when the car gets heat soaked in a parking lot will it throw AC consistently at a setting of 76 auto.