[Formulajones]

Originally Posted by 78w72

strange how there are so few 93 stations as you go west from the middle of the country, wonder if its temps that make higher octane limited in certain areas of the country?

if you look at this 93 locator map, the eastern half of the country is peppered with 93 octane but right down the middle it drops off to just a few areas around bigger cities. there is definitely 93 in AZ, just seems to be concentrated around bigger cities. https://find93.com/

also what is strange is that western areas only have ethanol that has to be mostly produced in the midwest then shipped to the western states, yet in many parts of the midwest, like iowa for example that is the largest producer of corn in the country, we have the option for non ethanol gas at almost every station. straight 91 is priced about the same as 10% 93, so youre paying an arm & a leg for either premium option.

another thing ive realized is that 10% ethanol raises the octane about 2 numbers, so 10% 93 starts as 91 then gets 10% ethanol added, 10% 89 was 87 before the ethanol... & 87 with ethanol started as the crappiest gas you can get, 85 octane!

strange why nebraska is so limited on higher octane when its just as midwestern as iowa, i recently bought a 4runner from omaha, about 4 hours from me in iowa, i stopped to fill up at a station right off I80 exit for the trip home & all they had at every station was 87 with 10%, no other options, would hate to live around there with a hot rod!

Yep, a lot of that doesn't make much sense to me either. I remember reading from somewhere that a lot of these Western states rely on the same supplier from California. Nevada is similar, Arizona is the same and I think it reaches as far as New Mexico. At some point that supply chain stops and from what Scott was saying earlier, they have 93 octane and Sunoco gas stations, so what we are getting from the West coast doesn't reach to Texas apparently. No Sunoco stations out here either.

In Ohio we had 94 octane from Sunoco stations, and that's all I used. All the other places like BP just had 93. Oddly when we lived in Ohio and would travel out of state, I'd hit other Sunoco stations (when I found them) like in Indiana or Kentucky for instance, they would only have 93 like Scott mentioned.

There just doesn't seem to be a lot of consistency, which is why I'm a little cautious of how I build an engine to run on todays fuel. I've avoided the E85 stuff just because it's just not available at enough places and I don't want to back the cars into a corner if you know what I mean.

The best way to deal with all that on a classic car is to go EFI and use a flex fuel system. Big money, lots of tuning to get it right, but sweet when working properly. The rest of us with carbs just have to be cautious with how it's built, how it's tuned, and run the best cat pea we can find.