Octane rating

I used Sunoco 112 leaded. Maybe overkill in a LP 1275 with 11:1 compression but in my vintage 1275 at 14:1 it was needed.
EZ
 
Used to use 115 in our 16.1 but can''t get any higher than 112. We use the 112 in the 1275 at 11.1 cr and hope it works in the 16.1 once we get the new car finished. Going to try to get to 12.1cr in the 1275 if we don't get the car sold.

Bob
 
I’m running Sunoco Standard - 110 octane in a 12:1 level 2 motor.
We originally ran 112, but tested the 110 early in 2022, and found it to be fine.
 
I'm moving all my cars to unleaded in anticipation of it being outlawed in some states. All my cars are limited prep 12:1 or less.
 
I used whatever ethanol-free was available at the station closest to the track, typically 92. silly rotaries.
 
My favorite is 100LL Avgas. (1.6 LP HP VW). Half the lead of most race gas, long shelf life and highly consistent, and typically quite a bit less expensive. What's not to like? Can be hard to buy as it's illegal to sell for street use so some FBOs interpret that (incorrectly) as only allowed to sell into airplanes.

BTW, "100" octane rating avgas is measured a bit differently but is similar to a 100 MON car gas octane. Car street and race gas is quoted as (RON+MON)/2. 100LL Avgas is probably around 105 (R+M)/2.
 
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Glad to see the Prod Forum back. Maybe its been back a while but it just let me in today.
I'm same as Al, I'm a long time (30 years?) user of 100LL Avgas for all the exact same reasons Al mentioned, although my current engine is only 11.5:1
 
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