Man, it seems almost all the threads in this forum are about problems!!

I have a different kind of question. My '09 535 has the zoned air conditioning for the front. Is this a sophisticated system that only runs the compressor when needed to keep the temp at the set level or does it work like most automobile systems and is regulated by the line pressure and the temp control just regulates how much outside air is introduced.

 

.

 

Well,,,, that was an informative response!

 

I'm pretty sure its regulated by the line pressure and the temp control just regulates how much outside air is introduced just like every other car. I've never heard the a/c condenser turn off with auto a/c, only when I press the button to turn a/c off myself.

 

That's kinda what I'm thinking. It would be nice if they would come up with a more sophisticated system along the lines of a home unit that only runs when necessary. My reasoning is for the gas savings. I know I'm not supposed to be worried about MPG when driving an auto in this class and that it really doesn't make that much difference (1 or 2 MPG?); but with talk of $6/gallon this summer...

 

Yes some cars: like Lexus, on some model (my did on 04' RX330) air-conditioner compressor is cycling. I could hear it, click noise when compressor kick on. But I think this system was not cooling efficient, even it safe some gas.

 

As far as I know all auto compressors cycle on and off. Like I questioned in my original post I am wondering if the system on the 535 works like the most common system used; cycling on and off regulated by line pressure. Or is it more sophisticated, cycling on and off by demand for cooling needs.