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Audi A/C power sap

zm@mhcnet.att.com writes:
> > >BTW, I also find that the AC on my '87 5000 CS TQ saps a lot of power. I was
> > >worried that the AC compressor was putting too much load on the engine due to
> > >some problem (low/high freon, etc). When I checked with the Audi dealer, the
> > >service manager said that this is the case with the Audis, there is nothing
> > >wrong. I just shut off the AC temporarily (press the ECON button) when
> > >I need to accelerate quickly or while passing.
> > >
> > 
> > Actually, I have never driven a car (of any make) where this wasn't true...
> > 
> > Well, except for that old '79 Caddy with a 429 under the hood.. but at
> > 10mpg, whaddaya expect?
> > 
> I realize that the AC puts a load on ANY engine. What I was referring
> to was an excessive load when I said it "saps a lot of power". On my Audi I
> can feel a *significant* drag on the engine the instant the AC clutch engages
> [...]

On my Audi 5000 turbo I don't think the effect of the A/C engaging is too
bad, unlike my Audi 4000, where it is definitely very noticeable.  On most
Audis, the A/C compressor will also cause the idle stabilization system
to increase the idle speed slightly.  Perhaps it is this that you are
noticing?  Also, there is no need to turn off the A/C when passing for
more power.  The car does this for you.  Most Audis have a A/C
kickdown/cutout switch that disables the A/C compressor when you floor
the throttle.  There is also an over-temperature cutout, such that if
your engine is overheating, the A/C compresor will disengage to reduce
engine load.  A look at the A/C section of the Bentley manual's electrical
diagrams is very enlightening!

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