The one factor missing here is that the method of calculating octane has
also changed and you should add 5 to today's octane number to get the number
from yesteryear. 102 from back when is 97 in today's numbers.
Jim Altman jaltman@altlaw.com Illigitimi non Carborundum
http://www.altlaw.com/metro/jaltman.html 69-TR6 80-TR8 W4UCK
-----Original Message-----
From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]On Behalf Of J.H. Roulleaux
Sent: Wednesday, May 17, 2000 7:04 AM
To: triumphs@autox.team.net
Subject: RE: unleaded gas
I think lead is not the major problem with modern gasoline to be
used in our cars. The modern gas is designed for todays cars and
has to fullfil ecological requirements.This is all in contradiction to
the prerequisites to the combustion in old engines. My TR6 manual
states that the "minimum" octane rate to run the engine is 102,
and this is far from the max 98 offered today. A lead substitude
with octane booster , like Millers VSP, could eventually bring it up
to 100, but this is still too low. When I bought the car in 73 the
highest gas rate sold in Europe was 105 octanes. AVGAS used in
Proplines used 110. I remember the problems we had in our Flying
Club when 100LL was introduced, to use it in cars is not wise,
because the additives in this fuel are designed to drive aircooled
engines at around 2700 RPM. I believe there may be less pinking
but other problems might develop.
Regards - Jean R. 70TR6 PI
60 TR3A
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