Turn off the AC first or turn off the engine first?

[HavenRose]

Turn off the AC before turning off the engine. Here is relevant information:1. Reason for turning off the AC first: If you turn off the engine first and then turn off the AC, the next time you start the car, the engine will start with the AC running, which undoubtedly increases the engine's load. Besides increasing fuel consumption, it also causes damage to the engine itself.2. After the car has been exposed to the sun: When the car has been exposed to the sun, if the outside temperature is 35 degrees Celsius, the interior temperature can reach 65 degrees Celsius within 15 minutes, causing the concentration of toxic gases inside the car to be 5 to 7 times higher than usual. Therefore, you should open all four windows for ventilation, then start the engine and turn on the AC. After blowing out the hot air from the AC, turn on the AC cooling switch. After cooling for 1 minute, you can close the windows, effectively preventing the harmful gases inside the car from escaping.

[MacViolet]

Having driven for over a decade myself, I believe it's best to turn off the AC before shutting down the engine. Think about it - the engine bears a significant load during startup. If the AC is left on, it creates additional startup load, which can easily damage the starter or battery. I've learned before that the battery requires high current during engine ignition, and running the AC increases current demand. Over time, this may shorten battery life. Turning off the AC before shutdown avoids this startup stress. Additionally, when parked, letting the AC fan run for a while longer helps expel moisture from the ducts, reducing bacterial growth opportunities. Since adopting this habit, my car battery lifespan has extended by three to four years, and there's no AC odor. This practice also saves some fuel, making overall maintenance more effortless. Simply put, turning off the AC first protects key components and enhances vehicle reliability.

[McParker]

From my personal observation and years of experience dealing with car issues, the sequence of turning off the air conditioning is crucial. Turning off the AC while the engine is still running prevents the battery from continuously supplying power after the engine is shut off, avoiding unnecessary energy consumption. The principle is that the AC system relies on the motor, and starting it under load increases pressure on the engine, potentially causing wear on components over time. I've tried shutting off the engine before turning off the AC a few times, and the result was a slightly harder start. Turning off the AC before shutting down the engine also helps keep the interior air clean by allowing the fan to dry out the ducts, preventing mold and ensuring fresher air the next time the AC is turned on. If you make this a habit every time you drive, it can significantly extend the battery's lifespan and reduce the frequency of repairs. In short, this habit saves energy, is eco-friendly, and helps maintain your car's overall health.

[VanColin]

As an environmentally conscious individual, I recommend turning off the air conditioning before shutting down the engine. This practice saves energy and reduces emissions, with the accumulated savings from each operation contributing to the planet's well-being. Turning off the AC before engine shutdown ensures smoother engine starts and prevents unnecessary battery drain. Additionally, it helps maintain a dry interior, preventing moisture-related bacterial growth that could affect health. After making this a habit, I've noticed significant fuel savings and extended component lifespan in my car. It's a simple, effortless action that takes just seconds each day.

[Gabriela]

I just started learning to drive, and I remember my instructor said to turn off the air conditioning before shutting down the engine. At that time, I didn't understand why, but after practicing, I realized it protects the battery and avoids overload issues during startup. After each shutdown, the car continues to supply power briefly, and leaving the air conditioning on would waste electricity. Turning it off before shutting down prevents this. The benefits include reducing odors and lower maintenance costs. I now stick to this habit and feel the car runs much smoother.