My rental, a Toyota Yaris, has a simple heater/AC and sometimes, with the fan on 1, the lowest speed other than "stop", and the temp on coldest, it's too cold.
The solution seems to be to move the temp towards warm, but when I do that, am I not using gasoline to run the AC and then mixing warm air with the cold air, that I just paid to create? If saving money were my only consideration, shouldn't I keep the AC all the way on cold, but turn it on and off, like a furnace or AC unit at home works? (Yes, of course the car is much smaller than the house and so I'd alternate between being too hot and being too cold, but this is an academic question.)
What about my own car, that has an automatic setting which it says will keep the temp at whatever temp I set it to? 70, 68, 72, whatever. Does this work differently from the simple AC in the paragraph above? Doesn't it also mix warm air heated by engine coolant with cold air cooled by the AC, using extra gasoline?
Isn't the only way to save money to set the AC all the way to the coldest, and turn it off if it gets too cold?
BTW, when I was here 53 years ago, I dont' remember there ever being a hot day. I was on foot, carrying a rucksack**, hitchhiking or walking around town.
**A strange backpack with a metal frame but one unlike any other one I've seen before or since. The frame was not two parallel sides, but sort of a figure 8 (but not that narrow in the middle. I might still have it in the basement, but the cloth is probably no good anymore.