Dennis
Fuel additive
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Joined: Dec 2023
Posts: 92
Likes: 15
From: Chalfont PA
Fuel additive
Hello,
The 63 convertible I recently bought has a 68' stock 350 engine with the original 327 intake and carb. I assume being an older engine I should be using the higher octane fuel at Sunoco. Do I also need to add a high octane additive. If so, what's everyone using?
The 63 convertible I recently bought has a 68' stock 350 engine with the original 327 intake and carb. I assume being an older engine I should be using the higher octane fuel at Sunoco. Do I also need to add a high octane additive. If so, what's everyone using?
Popular Reply
Aug 7, 2024, 09:27 AM
Race Director
Joined: Feb 2007
Posts: 15,468
Likes: 8,948
From: northern california
C2 of Year Finalist (track prepared) 2019
You don't need to add anything to the fuel. Use the lowest octane motor fuel which doesn't result in engine knock. Just drive and enjoy the car without overthinking anything.
Race Director
Joined: Feb 2007
Posts: 15,468
Likes: 8,948
From: northern california
C2 of Year Finalist (track prepared) 2019
You don't need to add anything to the fuel. Use the lowest octane motor fuel which doesn't result in engine knock. Just drive and enjoy the car without overthinking anything.
Race Director
Joined: Feb 2004
Posts: 11,039
Likes: 2,592
From: Del Boca Vista FL
Add a bottle of Lucas fuel system cleaner to a full tank and take a four or five hour highway drive at speed. That’s how fuel system additives work. After that just run quality gasoline and you should be fine. A base 350 will perform as well as it can on 91-93 octane. It might run OK on 87 octane but that’s not how I ever did it with any of my Corvettes.
People that use fuel system additives for around town driving are fooling themselves if they “feel” an improvement in power. I sold a lot of additives at the parts store to those believers. Product sales equal store profits.
People that use fuel system additives for around town driving are fooling themselves if they “feel” an improvement in power. I sold a lot of additives at the parts store to those believers. Product sales equal store profits.
Instructor
Joined: Apr 2022
Posts: 197
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From: IA
Le Mans Master
Joined: Feb 2014
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From: Richardson Texas
One caveat...I will say that Chevron with Techron does help to keep the fuel system cleaner, as well as, the combustion chamber. Not an additive, per se. I've run Chevron 93 octane with 10% ethanol for years and the cleanliness of the fuel system speaks for itself. JMHO.
Race Director
Joined: Jul 2018
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From: San Antonio, TX/Mahopac, NY
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I’ll add that 93 octane today is equivalent to 98 when these cars were new based on the new average octane formula.
Burning Brakes
Joined: Apr 2018
Posts: 985
Likes: 379
From: Northern Illinois
One caveat...I will say that Chevron with Techron does help to keep the fuel system cleaner, as well as, the combustion chamber. Not an additive, per se. I've run Chevron 93 octane with 10% ethanol for years and the cleanliness of the fuel system speaks for itself. JMHO.
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From: Coupeville, WA
Running ethanol-free 92 octane
From what I have read from multiple sources, ethanol can create issues with some of the materials used in older car engines. I searched around my local gas stations and found one that had ethanol-free 92 octane, which is what I run without any additives. All the other stations only had 87 octane ethanol-free, and lower octane gas did result in some knocking. So, I always go higher octane just to be on the safe side.