At 7:15 AM -0500 6/23/03, Keith Graves wrote:
>I just purchased a 1974 TR6 and have a basic question. What kind of gas
>should I use. I assume it was intended to use regular, the manual
>indicates an octane of at least 99. The best unleaded around me is only
>92.
Be aware that gasoline octane ratings in the US average the Motor and
Research numbers, which gives a lower overall number than what you may find
in the owner's manual. You should be fine using 92 octane pump gas. You
won't find higher for retail sale.
>Should I add an octane booster? Or I've also seen a releading solution.
A great deal of debate on these two subjects. Here's what I think and have
been told by people that know more than me: If you have a stock engine in
good running condition, set the timing according to the book and drive at
"normal" loads and speeds, you should be fine with 89 or 92 octane unleaded
gas. If you detect a bit of knock or ping under load, that's probably OK as
long as you don't do it for prolonged periods. Set the timing back a bit to
be safe, if you wish. If you want to go to the extra effort, get higher
octane fuel. The subject of lead vs. unleaded was set out to me by the
fellow that rebuilt my engine, whose only line of work is rebuilding
engines for the last 20 years. He told me that unless you run at high RPM
and load for extended periods or plan to put 20K miles per year on the car,
there is no reason to put hardened seats in the head. I have no reason to
doubt him.
>Also, is there a way to tell if the engine has been altered to accept
>unleaded?
Without inspecting the valve seats, probably not.
>Thanks for the help.
Happy to help.
Phil Barnes (peb3@cornell.edu)
Cortland, NY (nowhere near New York City)
'71 TR6 CC61193L (26 year owner)
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