ok well i now own my 350 z yess or me its my dream car and its mine now what one thing i want to know now is when i turn on the temp of my car to auto the a/c always turns on.... now the question i have is does the a/c take away HP or/and gas? so when it is on auto should i turn the ac off manualy?

ps sorry about these ovious questions im new to this whole thing

the AC will come on if the car believes it cant achieve the temperature you have the middle knob set to, w/o AC..can only be achieved via AC.

Sometimes the AC also kicks in to help defrost ( from its drying action)

depending on a combination of factors like outside/inside temperature.

Yes it does take some extra power to run the AC compressor and takes a bit away from your milage (except at hi speeds, there is actually less of a power drain to the car, by using AC to keep it cool, versus keeeping cool via open windows and their extra drag)

You can manually switch off the AC function of couise, just by gently pushing on the right knob.

And I often do so.

Fred..

Thanks fred this is the best fourm ever EVER lol