What was the octane level of premium gasoline in 1964? I have a 64 cutlass with high perfor. 330. Thanks!

 

Check this site

http://automationgame.com/phpBB3/vie...php?f=14&t=762


and, in particular, this paragraph

As the subregular and middle grades of gas came to market in 1962, the average octanes of gasolines in the U.S. now stood at 93 for regular, 99 for premium and 102 for the few super-premiums still left on the market. Those numbers would increase only slightly in the next few years to around 94 octane for regular, and 100 for premium by 1967.


The short answer to your question is that it appears that premium gas in 1964 averaged about 100 octane.

 

What have you been running in your car, and have you been having problems? Most gas stations today have premium that's, what, 93 or 94 octane. Have you been running that?

 

Here in Utah 91 is the highest but we do have one station with 110 never ran in my car but my dirt bike wow talk about a difference

 

To answer your question as best I can, the "standard" premium grade in the sixties was 100 RON octane, which is roughy equivalent to a modern 95 AKI octane rating. Some stations had higher grades, with Sunoco selling its "260" gas as either 102 or 104 RON octane (I suspect it may have varied by region), which would be equivalent to about 97 - 99 AKI octane.

So, your car was probably designed to run gas that would be between 95 and 97 octane using the current AKI system, which is at least a point above the highest octane you can get in most regular stations, which sell either 93 or 94.

Here's a nice version of The Story of Gasoline.

- Eric

 

Thanks for all of your help. The car was sitting ofr 25 years+, so I am in process of rebuilding carb/radiator, and dropping the gas tank to have it restored. I noticed the filler cap stated premium fuel only. The seller did not notify me of this, and I don't think he knew which 330 V-8 was in the car. When the car was unloaded from the carrier, the engine ran smooth and very quiet. Can't wait to get it on the road!!!