From: Paul Sayegh <paul@sayegh.org>
To: V-Max@sayegh.org
Subject: Re: Octane Requirements
Message-ID: <381E5DC2.CE5DD3F4@sayegh.org>

TC wrote:

>  I think you guys are pulling my leg
> because the label stuck inside my air cover, (fake gas tank lid), says
> 91 min octane !!
> Where are you reading 87 ?? The mechanic at my Yomama dealer told me
> to run 87 as well when I picked up the Royal ... I asked him why and
> he said .. "I don't know ... but we are supposed to tell everyone to
> do that during the break in period" ???? Go figure ??!?
> campbell

For most hydrocarbon fuels, including those with either lead or oxygenates, the
motor octane number (MON) will be lower than the research octane number (RON).
I don't know how other states rate octane but here it is MON + RON divided by
2.  The service manual even says "regular gas"

Your sticker says 91 RON  method, not accurate here!!  Stop throwing away your
money.

The lower octane during break in is important.  Cylinder walls glaze quickly.
When combustion happens the gas pressure forces the rings against the cylinder
walls by design.  This is why you don't need much ring tension to seal.  Fuel
that fires hard and fast without detonation aids this process of seating the
rings before glazing occurs

PS...what the hell is a Yomama dealer....he he
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