Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site othervax.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!linus!philabs!micomvax!othervax!ray
From: ray@othervax.UUCP (Raymond D. Dunn)
Newsgroups: net.auto.tech
Subject: Re: Gas Mileage
Message-ID: <757@othervax.UUCP>
Date: Wed, 5-Feb-86 11:30:04 EST
Article-I.D.: othervax.757
Posted: Wed Feb  5 11:30:04 1986
Date-Received: Sun, 9-Feb-86 05:26:13 EST
References: <576@adelie.UUCP> <103@dg_rtp.UUCP> <372@watmum.UUCP>
Reply-To: ray@othervax.UUCP (Raymond D. Dunn)
Organization: Philips Information Systems - St. Laurent  P.Q., Canada
Lines: 39
Summary: 

In article <372@watmum.UUCP> gvcormack@watmum.UUCP (Gordon V. Cormack)
responds to a previous article:
>> > I have noticed that my gas mileage drops by 15-20% every winter
>> 
>> I think the effect has two major components, and I'm not sure which is
>> greater.  First, the thermal component.  The car is breathing colder air
>> in the winter, and this heat must come from somewhere.  In this case, in
>> order to get cold air to expand the "same ammount" as hot air (and hence
>> provide the same amount of power) more gas must be burned.
>> 
>> Second, the humidity component.  Winter air is *much* less humid than
>> summer air.  A little water in the air works wonders for power output.
>> 
>> And oh, yes, if you have snow and ice sitting on your car, the wind
>> resistance goes way way up, so scrape it every morning.
>> 

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

I wish that when people made definitive statements, they would give their
reasons/sources.  Just because you pontificate "absolutely false", and
"absolutely insignificant" gives your opinion no more weight than the
original.

As I understand it, and have read in several places, high humidity *does*
have a significant affect on the airflow into the carb & cylinders, and
wind resistance of sevaral inches of snow *does* have a significant affect
on gas consumption - consider that (as reported not-so-recently in
Consumer Reports - that fount of information (:-)) driving with your
window wound down can affect consumption by 2 or 3mpg.

Any *informed* person like to comment (with checkable info rather than
opinions)?

Ray Dunn.  ..philabs!micomvax!othervax!ray