You're on the right track. The reason you lose power the higher you go is that the air is thinner (less dense). In a given volume of air, there is less oxygen. With less oxygen, you want to put in less fuel to maintain a constant air-fuel ratio.
I'm guessing you're confused about the idea of leaning it out. You don't really want to lean out the mixture per se, but rather, you want to maintain the proper air-fuel ratio, and at higher altitudes, this means removing fuel since nature is providing less oxygen. If you have a given air-fuel ratio of 14.7:1 (stoichometric, or chemically-correct) and lean it out to 16:1 or 17:1, yes, you should see better mileage, and slightly less power. Hope this helps.. -Dave -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dennis Kiernan Sent: Sunday, May 29, 2005 12:17 AM To: The Chevelle Mailing List Subject: Re: [Chevelle-list] mountain passes James Colgan wrote: > > I think you would want to lean out the fuel mixture the higher you > go . because the air gets thinner. less air less fuel.:) Is that true? I've never understood how it works. I have the idea that leaning it out gives you better mpg but costs you in power, and the problem with mountain passes is that you lose horsepower the higher you go. So I'm thorougly confused. (Nothing new).
