1991 porsche carrera 2

I have a 96 cab all stock just a weekend driver. Seems that the motor runs and sounds better with the ac on. I know with ac on it bumps the rpms up a little. I dont use the ac unless really need because I think in puts more strain on the motor. On newer cars with climate control is the ac always engaged? I guess we have climate control sort of. Should I leave the ac on all the time and control the temp with the temp control. . Does it hurt anything? If I turn up the rpms a little it will run to high with the ac on? any input. Thanks

CalvinC4S

No, the compressor kicks on when the temp hits a preset level.

Leaving the AC on will hurt power, mpg and will cause premature ware.

Runs better as in smoother? What RPM with AC off?
Maybe rubber breaking up in the fly wheel plates as a internet guess.

Ed Burdell

I get about a 10-25 rpm bump with AC on, and the idle smooths out.

Here in Ga, AC is on most of the time, anyway.

bart1

You might try searching ISV and see if you can find similar stories.

MarkD

+1

clean your ISV
If that doesn't do it, replace your ISV

Stealth 993

The car will run a bit richer with the AC on, so besides the ICV, you can also try cleaning the MAF & maybe checking the O2.