Miata Mailing List: December 1993, Message #205
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   From: Andy Poling 
Subject: Re: RE>Re: Texaco - Ethanol vs. MBTE
   Date: Wed, 22 Dec 1993 10:32:24 -0500

On Wed, 22 Dec 1993, Al Jenab wrote:
> I would think that because colder air is denser, it would 
> require more gas for the right fuel/air mix.  Since the volume of the 
> cylinders aren't changing, your engine would therefore need to use more gas 
> per combustion cycle hence lower overall mileage.
> 
> Am I on track here?  Any combustion engineers out there?

I'm not a combustion engineer, but I can tell you that you were doing fine
up 'til your last statement.  It's true that denser air will require more
fuel, but that's OK.  The idea is to stay near the stochiastic balancing
point that the fuel injection map dictates. 

The denser fuel/air mixture has an effect similar to raising your
compression ratio - it lets you pack more energy producing "stuff" per
swept volume into the cylinder on each cycle.  You have more power
available, but you are not required to use it.  :-)

-Andy (C/S Miata - Team Wannabee)

Andy Poling                              Internet: andy@jhunix.hcf.jhu.edu
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