Setting A/C thermostat to maximum coldest temperature

Is it true that if I turn the thermostat of my car’s Air Conditioning to the maximum coldest setting when I’m driving in the summer, this will eventually ruin the A/C system, (because I’m pushing it too hard)?


The AC compressor produces the proper pressure at all times no matter where you set the temperature setting.



The A/C is designed to cope with the worst situations continuously… However, that’s not true for all cars.

A colleague in Malaysia bought a Fiat for his wife. All cars sold there have air because of the humid tropical climate. The A/C on his wife’s car could not cope (cool sufficiently) and when he took it to the dealer he was told they could do nothing because “the car was not designed for tropical conditions”!!!

When I worked in the Middle East the preference was for US vehicles because of their powerful and reliable A/C systems. Rolls Royce’s original A/C design were by a company in Texas!

Anyway. your system will not destroy itself when set on maximum.

There’s some truth to that, as generally the more any mechanical contraption is used the sooner it will break. But it is not something I’d worry about myself. The AC system in your car will fail eventually if run long and hard enough, that’s certain. But the car may have been junked by then, or sold. You bought the AC to make driving comfortable, so go ahead and use it as much as you like. It’s designed to be used. It will probably never fail at all, or if it does, it can be easily, albeit perhaps expensively, repaired.

Setting the temperature to a warmer just adds warm air. This is how your defroster works, AC is running, this condenses out humidity and warm DRY air defogs your windshield.
So run it at what ever is comfortable.

Reducing the fan speed will lessen the demand on the system as will avoiding stop and go traffic. The greatest stress on the system is when the condenser pressure rises to the extreme. That is the result of the amount of heat added in the dash board evaporator and the amount of heat disapated from the condenser. Raising the desired temperature on many late model cars will, as @Gpierce001 mentioned, actually increase the load on the system. If you keep the AC maintained and operate it as intended you should get your money’s worth out of it.