A friend of mine swears by this though I never thought to bother myself. Any comments?

 

Even though I don't have an S...yes, I always turn the A/C off before shutting down. I can't think of a logical reason why or if there is even any benefit, but I just do.

 

So tell me what do you plan to do when you purchase a vehicle with climate cntrol?

 

its better because its leaves a skunk like smell if u leave the ac on and turn it off for a whileabout a year

 

Good O, guess there's no harm in that then.

Sleep better all

 

i always turn off the ac and let all the cold air run out b4 i turn off the car. i heard that it prologs the life of both the car and ac unit. i was actully told the exact reason why i should do this, but i dont remember anymore

 

hmmm, maybe a trip to the owner's manual is needed.

 

Yup I do.

When running A/C I turn off the A/C about 10-20 seconds before I turn off the car (usually before pulling up to my driveway) and leave the fan on. I usually crank up the fan a bit. IME, I've noticed this prevents that "mildew" smell. Gets rid of that condensation stuck in your vents.

 

It's good to turn off the a/c and let the fan run for a bit before you shut the car off to let the fan dry out the system of any condensation that may have built up and can eventaully mildew and make the car smell.

 

I turn it on immediately, esp in cold weather, and turn it off the for the last few miles. Here is why for both:

1) Switching on the air hastens engine warmup, as the heated air from the condenser warms the radiator and the engine bay

2) Switching off before shut down allows a lot of the heat that would soak into the engine compartment to dissipate prior to shutdown - this latent heat soak causes some of the highest temps an engine sees, and adds to the thermal cycling of the head gaskets and all the underhood rubber.

I actually have a large floor fan right in front of my cars, with the parking sensor I use to let me know when I am close to the wall mounted right on the fan. I switch the fan on to low to force cool the engine gently, allowing it to thermal down slowly, but eliminating the heat spiking. This is especially useful for those that park in garages where air flow is minimal. Mine is AC'd, but even outdoors, heat soak at shutdown is increased by the heat in the condenser and other AC lines. Actually, this cools the entire system - brake fluid, catalytic, etc.