High altitude, and low octane

[David Head]

And I was convinced mine was broke!

Robert Myers wrote:

> I will tell you this however, when I was at Pike's Peak with a buncha other
> audinuts, I could feel a definite seat of the pants decrease in engine
> output due to the combination of lower ambient air pressures and lower fuel
> quality.  I'm not positive that I could determine which of the two factors
> was the controlling factor but I suspect that my ECU was retarding the
> spark some to compensate for the fuel.
>