Rich Thomas wrote: > I got to wondering why this was. I was thinking it might have something > to do with altitude, and lower octane being OK, but that does not take > turbos into account. Or the MBTE/ethanol lack? > > So, can someone explain this? >
>From what I've read in the Gasoline FAQ, it's because the lower oxygen content in the air makes the fuel burn slower, reducing the octane requirement. As you noted, turbos are a bit of a special case, but most turbos have knock sensors and will cut back on boost and/or timing advance as needed to prevent knocking.
