Question about octane ratings....
Thread Starter
Pro
Joined: Oct 2002
Posts: 708
Likes: 0
From: somewhere south of normal
Question about octane ratings....
Today I was at my machine shop, to pick up my freshly machined block for the 383 I'm about to build. I got into a discussion with the owner about compression ratios. My current motor is @ 10.5:1 cr and I use 93 octane most of the time. Once in awhile I have to use 92. I have never had any ping or knock of any kind. The motor runs like a raped ape and has been very dependable as a dd.
Ron, the owner, asked me if I had ever tried mixing 93 octane with a lower grade. I said no, why would I? He said that mixing the two grades together actually raised the octane rating higher than using straight 93 octane. I've never heard this before, and don't see how this could occur. He said to just try it for a tankful. Ron has been in the business for many, many years. He and his son have a drag car, and he has done work for my good friend who recently set a national record in his class.
Has anyone ever heard of this before? Any chemists out there want to jump on this question?
puzzled in A squared
phillip
Ron, the owner, asked me if I had ever tried mixing 93 octane with a lower grade. I said no, why would I? He said that mixing the two grades together actually raised the octane rating higher than using straight 93 octane. I've never heard this before, and don't see how this could occur. He said to just try it for a tankful. Ron has been in the business for many, many years. He and his son have a drag car, and he has done work for my good friend who recently set a national record in his class.
Has anyone ever heard of this before? Any chemists out there want to jump on this question?
puzzled in A squared
phillip
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
I work for a well known oil company. If you mix 1 gal 93 octane with 1 gal 87 octane, you'll end up with 2 gal of approx. 90 octane. The ending octane rating will always end up being between the two octanes you're mixing. 
Thread Starter
Pro
Joined: Oct 2002
Posts: 708
Likes: 0
From: somewhere south of normal
Originally Posted by marshrat99
I work for a well known oil company. If you mix 1 gal 93 octane with 1 gal 87 octane, you'll end up with 2 gal of approx. 90 octane. The ending octane rating will always end up being between the two octanes you're mixing.
This is what I figured too, but I didn't want to debate this with the guy.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by HDIronman
I can do that, but is it factual....????
Dep
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