At 9:33 AM -0600 6/14/01, Richard A. Jones rearranged electrons to say:

>>>In Texas and New Mexico ALL of the regular gas
>>>was 86 octane.  Anyone know why this is so?
>
>Regular is 86 here in Colorado.  I've been told that
>the refiners lower it because of the altitude.  I have
>noticed 87 at lower altitude places....

Gasoline has different octane ratings because the different levels
inhibit premature detonation before the spark plug fires (knocking).
Since this can damage the engine, it is important to put the proper
octane gas in your car (see the owner's manual for details)

At higher altitudes, there is not as much oxygen in the air
(explaining why people get winded more easily in places like
Colorado) and thus it is harder to ignite gasoline. For that reason,
it is not necessary to use as much octane in your motor fuel. Most
manuals are written to assume you'll use your vehicle at altitudes
around sea level because most inhabited areas of the US are pretty
close to it.

Feed your car the wrong octane level, and chances are the ECU will
inhibit your ignition timing to prevent knocking and cylinder wall
damage. A friend of mine came to me asking why his Camaro "isn't
making Mustangs shrink as fast as usual" and I asked him some
questions, including what gas he was using. It turns out he was using
89 instead of the recommended 91 -- and his own engine was slowing
down to prevent expensive damage later on. I think this was the
8-cylinder engine...

Not enough time has passed to know if switching back to 91 octane
solved the problem, but I suspect that it will.
--

-----

Jennifer - ncc876@yahoo.com
... knee-deep in the hoopla ...

_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com