Is it Bad to Turn Your Car Off and On With the AC or Heat Still On?

How many times have you started your car and the air blows in your face? I always try to remember to turn everything off before I turn off my car. Well except the radio.

Anyway, at some point in my life, I was told to always turn off the AC or heat, depending on the season of course before turning off my car because it's bad not to. I never asked why I just did it so now I decided to check into this and see if it's really necessary.

According to the Motor How To website, I was absolutely doing the right thing by turning off the AC or heat while I was growing up. However, things are different now.

With newer cars, it is not harmful to leave the heater on or your air running while turning your car off and on. It used to be something that could slowly affect the engine over time with added stress on the battery according to Motor How To but we're in different times now.

Vehicles can handle you starting your car and turning it off just fine with heat and AC still on because modern cars have fuel injection engines and don't drain the battery like older cars with a carburetor.

I have no idea what a carburetor is but according to Motor How To, if you're still driving a car from the 1980s or earlier then this rule of turning everything off before shutting your engine off still stands.

According to the website Your Motor Fix, modern cars are also wired in such a way that whenever you start the engine, the AC compressor clutch is disabled so the electrical load on the engine is off as well.