Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 exptools; site laidbak.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!laidbak!jeq From: jeq@laidbak.UUCP (Jonathan E. Quist) Newsgroups: net.auto.tech Subject: Re: Gas Mileage Message-ID: <716@laidbak.UUCP> Date: Sun, 9-Feb-86 23:43:30 EST Article-I.D.: laidbak.716 Posted: Sun Feb 9 23:43:30 1986 Date-Received: Tue, 11-Feb-86 07:51:29 EST References: <576@adelie.UUCP> <103@dg_rtp.UUCP> <372@watmum.UUCP> <757@othervax.UUCP> Reply-To: jeq@laidbak.UUCP (Jonathan E. Quist) Organization: LAI Chicago Lines: 23 Summary: re: comments on air temperature and humidity vs. fuel economy Cold air is more dense than warm air, so a proper fuel/air mixture requires more fuel per unit volume of air. Humid air is less dense than dry air, so it would seem reasonable that humid air would require less fuel per unit volume of air for the proper mixture. In aircraft operating at high altitudes ( in this case, greater than about 5000 feet above sea level) the fuel/air mixture is leaned to increase fuel economy. (In the case of a non-supercharged piston engined aircraft, the decrease in fuel burn rate can be greater than 25%, if memory serves me correctly.) I realize I'm over-simplifying things quite a bit, and I'm probably ignoring several factors, but my point is that air temperature and humidity will affect fuel economy. Jonathan E. Quist ihnp4!laidbak!jeq