100ll
Thread Starter
Instructor
Joined: Feb 2021
Posts: 230
Likes: 206
From: Port St. Lucie, FL
2026 Corvette of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Winner - Unmodified
100ll
Much has been said about Octane ratings lately. But would there be any harm in filling up my C8 while I was fueling my airplane with 100LL?
Melting Slicks
Joined: Sep 2020
Posts: 2,832
Likes: 2,150
From: Kelso, Wa
Avgas contains lead, which will ruin your catalytic converter.. That's just the start of potential problems...
Do a google search "problems using avgas in cars" and you'll get your answer(s)
Do a google search "problems using avgas in cars" and you'll get your answer(s)
Instructor
Joined: Sep 2024
Posts: 204
Likes: 147
From: Phoenix AZ
2024 C8 of the Year Finalist - Modified
In the short term, little damage to your cats, but what's the benefit? Not going to see any appreciable performance gain, and the last time I bought avgas, it was more costly than 91-93.
Race Director
Joined: Sep 2000
Posts: 11,139
Likes: 1,910
From: Missouri City, TX
Octane is not a measure of energy content per unit of volume. If the engine provides max performance with 93 octane (no knocking), then I do not see higher octane unlocks more performance unless the ECM tuning gets changed by reprogramming.
Safety Car
Joined: Jun 2006
Posts: 4,008
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From: Ashland, OH
Administrator
Joined: Mar 2001
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From: In a parallel universe. Currently own 2014 Stingray Coupe.
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Yeah, I would just stick with premium gas like you can get at a regular gas station.
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CF Community Team
Joined: Apr 2016
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From: Pittsburgh
2025 C6 of the Year Finalist - Unmodified
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No more performance will be achieved & you will eventually ruin your O2 sensors & cats
Le Mans Master
Joined: Apr 2020
Posts: 6,379
Likes: 3,294
This sounds like something floating around in the rumor mill from when I was a teenager - Putting High-Test in a car only needing regular will be faster at the track. Of course, no change to the distributor at all regarding the spark advance or decrease was performed.
Safety Car
Joined: Jun 2006
Posts: 4,008
Likes: 1,487
From: Ashland, OH
Called living in the past. Someone convinced someone a bad idea was good and it kept getting repeated. Tell a lie long enough and it becomes fact.
Le Mans Master
Joined: Apr 2020
Posts: 6,379
Likes: 3,294
I love the saying when I purchased my 2020 Game Changer - "
buy a first year model." It was 
over and over. My Game Changer has been just fine, aside from the free second Tx.