A friend of mine tells me: "...I never turn the A/c on as soon as I start the car. I wait until I start to drive, and reach about 50 mph, so that the engine has passed the high rpm areas, and have gone past o/d, and the oil has started to circulate well. only THEN i turn on the a/c...this is a lot better for the engine, and helps longevity.. turning the a/c on as soon as you start the engine is bad..." Is there any truth to this? I know it can't harm anything to turn on the a/c after the car reahces a certain speed, but is there a real advantage? what do you guys think?