FYI- octane numbers

["estorhok" <estorhok@domain.elided>]

Not to express an opinion here, but FYI.

Octane is expressed in three numbers, MON, RON, PON.  MON and RON are actual
tests, while PON = RON+MON/2- US pump octane.

The 2 tests for MON and RON are quite different, typically resulting in
differences of about 10 octane numbers.  example- for a given fuel, you
could have 94 RON and 84 MON, which would give you a result of 89 PON.

So what does this mean?  Well, in Europe, the numbers are expressed ONLY in
RON (well, as far as I know).  And I do recall that my Alfetta asked for 95
RON, which would be 90 PON.

I still run premium fuel in my 73 GTV (93 PON= 98 RON), but my excuse is
that I mostly autocross and track the car, so I'm being careful. (only
opinion line...)

Eric Storhok
Ann Arbor, MI

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