AC vs MPG

[Phil and Judy Rose <pjrose@servtech.com>]

Now that my trip computer is functioning, I hardly have time to focus my
eyes on the road ahead ;-)

One of the things the computer seems to be telling me is that the AC takes
a pretty big (bigger than I expected) bite out of the fuel economy.  For
example, when cruise-controlling on a level stretch I engage the AC and
immediately see the instantaneous MPG drop by about 3 miles/gal! Isn't this
a bit too much? I'd expect 1 or two at most, but don't really know the
typical cost. My AC clutch seems in need of repair as indicated by the
occasional squawking it does. I wonder if there's (that much) extra drag
from a bad AC clutch?

As a side issue: With the AC off ( windows closed) at 70-75 mph on gently
rolling, but basically level expressway terrain--my '89 100 (automatic) is
getting a little under 24 mpg. This is based on the computer and a fill-up
after a couple of 150 mile trips. Is it reasonable to expect much better?

Phil
'89 100

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