Gas Distribution & Octane

[Steve Cassani]

Several of the replies to current threads concerning octane suggest I have a knowledgable audience for my question: Why is the highest octane available in Montana 91 when retailers in Washington, Idaho and Wyoming offer 93?

The common brands in Montana are Coneco, Exxon and Sinclair. All of these refiners supply 93 octane gas for sale in other states.

What's up?

[Curt C.]

I assume you are at 2000 plus feet above sea level? Higher elevations have less dense air which yields less tendency toward detonation. We only have 91 here in Vegas as well. We are right about 2000 feet above sea level.

[Steve Cassani]

The elevation at Manhattan MT is 4200; Bozeman is roughly 4400. Missoula, near the west boudary of the state, is 2200, I believe. Kalispell, in the northwest corner of Montana, is 440 or so. The average elevation for the state is well over 2000 feet.

Thanks for your help!

[Rick Parker]

Good question Steve. I believe California tops out at 91 Octane also. There are different math formulas for determining octane ratings of fuel. The formula is on many of the pumps here. I think California's is an average of "Motor Octane and Reseach Octane". We have some sort of additive package that effects it to some degree.

Rick

[Steve SPF 517]

A Cobra in Montana!And another Spf owner to boot! I frequently visit a relative in Bozeman (Bridger Canyon area) and have yet to see one there. We can meet at the Oasis for dinner, are you ther full time?