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Old 07-19-2009, 02:11 AM   #20 (permalink)
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Originally Posted by ConnClark View Post
Not only does power drop with altitude but engine efficiency does as well. It all comes down to whether the drop in aerodynamic drag is greater than the drop in engine efficiency. I would tend to doubt this is the case though.
Are you referring to the case of carbureted engines? Most non-aviation carbureted engine have fixed jetting for mixture, so yeah efficiency does decrease because the mixture becomes richer. You have to rejet the whole carburetor to fix the problem. Modern injected engines maintain a stoichometric mixture constantly, so that wouldn't be a problem.
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