I don't have equations, but I think the gas companies have done that
already. The lowest octane gas here in CO is two points lower than the
lowest octane at sea level. Like I said, no formulas, but there is a two
point drop in the ~6000 feet between here and sea level, so maybe you
could approximate -1pt per 3000ft.
James Nazarian
'71 B roadster
'71 BGT rust free and burnt orange
'63 Buick 215
"Aerodynamics are for people who cannot build engines"
Enzo Ferrari
On Tue, 4 Jul 2000, Andrew B. Lundgren wrote:
> That is exactly correct, and what I have been looking for is equations
> to figure out the the right number.
>
> On Mon, 03 Jul 2000 21:19:17 -0700, Bullwinkle wrote:
>
> >This response is just hypothetical and I have no hard facts, but:
> >
> >At a higher altitude the air density is less. Even though you are
>compressing it
> >at the same ratio, the compressed charge would have less density. This is
>the
> >same effect as compressing the air at a lower ratio at sea level, i.e. air
> >compressed with a lower ratio has less density than one compressed with a
>higher
> >ratio. We know that lower compression ratios need less octane at sea level,
>so
> >it would make sense that at higher altitudes a lower rated octane would be
> >needed.
> >
> >
> >
>
>
> Andrew Lundgren
> Lundgren@iname.com
> http://www.itwest.net/~lundgren
>
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