Does it really work, how good does it work, and is one better than the other? Or should I just bite the bullet and treat my '72 U code Supreme to a dose of Sunoco 260?

Just curious...😁

 

The stuff I’ve seen and used occasionally some time ago was Kemco’s Octane Supreme 130. Nothing else I’ve seen that comes in a small container works like that product. Other products used or I have knowledge of by friend’s experiments were nearly useless. I had pretty good results with toluene but it was purchased in a 55 gallon drum that I can’t imagine the cost of nowadays. I had some high compression engines back then and even used water injection to allow running them on pump gas, preferably Sunoco premium after the real 260 went away.

For years I ran 100LL in all my old cars and it was great stuff, especially since I got as much as I could transfer and transport for free via sump fuel at the airport. Great for mixing with pump gas where the octane is not needed and that should take care of any potential lubricity issues. After running that stuff for years, long ago, I still am repulsed by the smell of pump gas compared to the sweet, race gas like aroma of 100LL.

Ran Jet-A in the house for years which I could take for free as well. It may also have found it’s way into a diesel pickup but I can neither confirm or deny that.

​​​​​​….

 

What is the problem you're having ?

 

Not having any problems...just curious if it would squeeze anymore out of the 455

 

Is your engine original with the 1972 factory 8.5:1 compression ratio? If so, you don’t need high octane fuel. And even if the engine isn’t factory original, if there’s no pinging with the fuel you’re using, then there’s nothing to be gained by using a higher octane fuel. All it will do is lighten your wallet.

 

It's not stock...W-30 cam, .030 over with headers, Performer intake and Holley 770 Street Avenger. No pinging on 93 pump gas, and she'll walk sideways off the line, so Ill put this to rest. Thanks for the advice 👍

 

My 66 442 3X2 9.6 CR made 406 HP on the dyno with Shell 93 and 411 HP with VP 110. You be correct. I have used this before and is a great product.
https://www.ebay.com/itm/14468616547...hoCJ5kQAvD_BwE

 

I've used Torco additive. It stops run on with a bad tank of fuel. No performance data, though.

 

Just adding octane booster without changing the tune will do nothing.

 

I appreciate this discussion. I live in Colorado at about 6800' above sea level, and the closest I can get to High Test for my stock '68 4-4-2 is E-10 91 octane. Is there any need for me to run such a booster product?

 

I think you'd suffer from an octane booster since the air density is less at altitude. You're better off w/ a lower octane.

 

Thank you, Norm. I assumed the opposite.

 

In and of itself, octane booster won't make a bit of difference. It won't make your engine more powerful or make it run better. What it will do (if you get a good one) is allow you to run more timing without experiencing spark knock, which should have a beneficial effect.

 

A lot of refiners are using ethanol as an octane booster. All the old ones such as lead and MTBE are long gone. So if your adverse to having ethanol in your fuel, then going with premium is going in the wrong direction.

 

IOW, to reap the benefits, Id have to bump the timing up, then when I switch back to 93, I'd have to dial it back? And hypothetically speaking, what about carb and idle adjustments?

 

Yes, you can experiment with advancing the timing and speeding up the curve if you have an effective octane booster. I would just establish the timing for the octane you're using and leave it -- too much of a PITA (for me, anyway) to be constantly adjusting back and forth.

And yes, doing a distributor tune may necessitate some carb adjustments.