why is rich better for power ??

[jb24 at chrysler.com]

Have we resolved this yet?  On methonal-burning turbo CART cars (nice
simple hydrocarbon), I was under the impression that exhaust
composition was still rich.  Maybe a better question is 'How do EGO
sensors work?'  If all the oxygen burned yields stoich, i.e. 0% oxygen,
how do you read less than 0% (rich)?

My bet is combustion efficiency is never 100%, and thus stoich is more
than 0% oxygen.

John Bucknell