Where can I find 91 Octane in Milwaukee?

[Sagaris]

87, 89 , 93 That is all I can find at the local gas stations. I have a 91 octane chip and want to run 91, since I believe I will have better performance than with 93. It also costs less. Has anyone seen 91?

[s_ribs]

You do realize that a 91 octane chip only means nothing less than 91 right? It isn't optimized for it. And if there isn't 91 octane near any place you already go - you'll spend more money looking for it than the few cents difference there may be! ;)

I'm stoked for 93 being the standard premium (it's 91 here).

[MrSlacker]

Just mix 89 and 93

[Van Westervelt]

I'm stoked for 93 being the standard premium (it's 91 here).

Its actually 92. ;) But you probly havent noticed since they still pump it for us.

And running 93 in your car is just as good if not better than running 91.

[s_ribs]

Quit stalking me and correcting me JA!!

[Sagaris]

Yeah, I understand that it means no less than 91 but (Correct me if I am wrong) my theory is that 91 will burn slightly easier. Therefore with 93 I may not get as complete combustion as I could by running 91. I know it wont yield a huge difference but I would like to give it a few tanks to see if I notice any changes. If I can find it that is. I have considered mixing 93 and 89, other than looking like a dink, I believe the station wont allow multiple uses of a credit card at the pump within a certain timeframe to avoid people gassing up with stolen cards, just something I have heard.

[s_ribs]

You are correct (sort of). The higher the octane number the slower it burns. The lower, the faster. The reason tuned chips require higher octane is because lower octane is burned too quickly. The area of focus in your thought process is a bit off though. Slower doesn't mean it won't all get burned. Think of it as a more controlled, even burn. Low octane causes issues in higher tuned engines because it's gone too fast and is less consistent.

My thoughts? No way I'd spend time looking for 91. No advantage to it. You will not gain power, smoothness, or anything by dropping 2 octane points. Especially on those super hot summer days your car may actually be happier with 93. I can't imagine the price difference alone would justify looking for.

[Vince30]

Octain is the ability to control burn, the higher the octain the slower but more controlled and constant the burn. That being said it will not hurt to run 93 but ignition will be delayed and performance/economy will go down from what is supposed to be ran. However if you put 89 the spark will be to advanced and cause detination, witch is not good.