I have a 1991 supra manual with just 75k miles on it, wanted to know if leaded fuel is acceptible for some time, and what 100 octane fuel is possible to get today. I am seeing what I think is detonation on WAWA 89 ethanol free with my own added K and n octane. I didn't see any issues with shell 90 ethanol free with my own Lucas octane before they closd down. I'm trying Shell 93, but still feel horrible.
its one from oversees in japan right hand drive, where 100 is standard to them
What method is used to calculate octane rating in Japan? In the U.S. it's the average of the RON (Research Octane Number) plus MON (Motor Octane Number), frequently written as (R+M)/2. The octane ratings in other countries cannot be assumed to match those in the United States.
https://en.wikipedia.org/wiki/Octane_rating
You may have some other problem, like carbon buildup increasing compression or ignition too far advanced.
Where did you find leaded gasoline?
the fort lauderdale airport is where my older collector friends go for it. they did warn me of the possibilities of it eating my sensors over time, but also informed me they are surprised my car is still alive without 100 octane.
why would it not "be alive"? It's a street legal car designed to run on pump gas.
its one from oversees in japan right hand drive, where 100 is standard to them is where this idea comes from mine is dying without it and has a compression ration that requires it.
Leaded gas will quickly poison your catalytic converter, assuming your Supra still has one. You need to figure out why you are experiencing detonation. Unless the engine has been highly modified it was designed to run on unleaded gas.
https://itstillruns.com/leaded-fuel-affect-catalytic-converters-7826145.html
I have no mods, just new stock parts done. I have been told to try SUNOCO 100 octane, and something about a bad idle circuit possible.
There is a difference between leaded fuel and alcohol free fuel. It's not legal to sell leaded fuel. In fact it's banned in most things except car batteries.
... and ammunition, fishing tackle, electronics, aviation fuel, sailboats, roofing, crystal etc etc ....
It's not so much "banned" as it is disfavored.