As you probably know, California has strict regulations on its gasoline. They put so many additives in it that by the time its all said and done its not true gas any more!! I have had my car in the shop several times do to the gas we have here. Sometimes my engine will stall and idle erratically. The dealer cant find anything wrong with my car. They said it was do to the fuel. They also said that they get 5 or 6 cars in a day with the same problem I have. I have also noticed that in California you can only get 91 octane fuel, but in everyother state you can get 93. What gives????

I've noticed that the colder the climate, the higher the octane available. I know what you mean by the CA gas, though. I'm a native. There'* a 'magic' EPA line drawn across N CA. Regulations are less strict north of the line than south. Or it was that way a few years back. Remember when the spray paint regulations changed? You could still buy the 'bad' stuff in Sonoma County on the north end, but not in Santa Rosa to the south. Weird.

With all the additives and EPA crap, I'd be paying particular attention to your throttle body. I bet it gets nasty faster than everywhere else.

I'm not sure how the People'* Republic of California does it, but here in the United States, the octane that a particular station sells is determined partly by the local elevation. The higher the altitude, the lower the octane offered. Here in Cheyenne, Wyoming, elevation 6200 ft., regular unleaded is 85 octane. Go into Nebraska where the elelvation drops to below 3500 ft, they sell 87 octane.
So part of the reason you see different octanes at different locals is the altitude.

Here in Toledo we have 87 Octane - 93 Octane

Same in Michigan

most common octane for premium here is 91, but occassionaly I'll see 92. Oh yeah and it'* now $2.15 a gallon

Here in Indiana it'* 87 Reg, 89 Silver, 93 Prem.

In Iowa we have 87-91or 92

Who else has ethanol blended medium grade (90~91)

Yeah, corn :o

We have 87-93 here. Most grades are 89 - Regular, 91 - Super grade, 93 - Premium grade (names something like that). Although there are 2 stations in the Twin Cities that sell approx. 100 octane out of the pump.

We have 87 or 89 regular, 91 medium or 93 supreme. One gas company, Sunoco has Ultra 94, but it is very $$$