🚀 go-pugleaf

> > > I have noticed that my gas mileage drops by 15-20% every winter
> > 
> > [insert foot in mouth, give wrong "answer"]

> I didn't notice a "-)" on this posting, so I am taking it seriously.

Uh.... thanks.   I think.               :-)

> The second point (about humidity) is absolutely false, and the
> first and third points (heating cold air and wind resistance of 
> snow) are absolutely insignificant.

Since you are right, and I'm wrong, I'm reduced to picking nits.  So
here goes.  While you are correct that the relative humidity is not
particularly lower in winter than in summer, the absolute humidity *is*
significantly lower.  This *can* have an effect on the power output of
the engine, but it is (I am now fairly sure) quite minor.

Wind resistance now... there I think you are slightly wrong about the
importance of the effect. I agree that the effect is *relatively* minor,
but wind losses go up rapidly with speed, and if most of the travel time
is spent at 55 or higher, this can amount to a couple of percent
difference.  Nothing like the >15% in the problem, but certainly not
absolutely insignificant.

In any event, the *major* effects are more likely increased per-trip
overhead (choke "wastage", warming up too long, stiff power train until
warmup, etc).  The best bet for "solving" the problem is to make sure
the car is tuned properly, make sure the choke isn't partially stuck in
cold weather, and don't waste gas by warming up the car before getting
on the road.  But then, I'm known to give bogus answers, so why should
you listen to me?

And, of course, I apologize for jumping in with a misleading and
incorrect response.
--
(Basil Fawlty, rehearsing to himself while going to apologize to a guest:)
    "I'm sorry, I made a terrible mistake...
     I'm sorry, I made a terrible mistake...
     I'm sorry, I made a terrible mistake..."
(finally reaching the guest's room, he strikes a pose, and says:)
    "I'm sorry, my wife has made a terrible mistake!"
--
"Pay no attention to that man behing the curtain!"
-- 
Wayne Throop at Data General, RTP, NC
<the-known-world>!mcnc!rti-sel!dg_rtp!throopw