Ken, that would be correct.

At altitude that air density becomes less and less in relation to the amount of
fuel going through the engine, so fuel air mixture goes to the rich side, you
get incomplete combustion and a loss of power is the consequence. There may be
some automatic mixture adjustment built into the F/I but it is probably small
and the limits are reached very quickly if its there at all.

As you may well know, fuel injectiojn systems and some of the big carburetors
on piston type Aircraft powerplants have auto-mixture controls, and smaller
aircraft have manual mixture controls that can be operated from the cockpit.
Never saw an automotive vehicle so equipped.

John Rodgers

KENWILFY@AOL.COM wrote:

> I don't know about better mileage but I experienced power loss and rich
> running going over the Sierra Nevadas a couple summers ago.  I think it was
> 12,000 ft or maybe a bit more.
>
> Ken Wilford
> http://www.vanagain.com
> John 3:16
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