Quote Originally Posted by yapoy86 View Post
Leaving it at 23 or 24 deg will not make your compressor last longer. For cars without climate control it will matter because the more you go higher the longer the compressor works.. but for cars with climate control the compressor will run to maintain cold air.. now if you set to say 23 deg, the system will just mix hot air to your air vents to achieve 23 deg..

As i have observed.. at 18 deg mazda compressor still turns off and on.. it may work harder at 24 deg coz your system is mixing hot air into the cabin..

You can observe this with your car.. you can feel the compressor disengaging even at 18deg
Again I'm basing this on experience. Haven't had AC problems with any of my autos left at 23-24C Auto for the past decade, Mazda including. Ultimately its your car so feel free to set it as you desire.