Interesting fact I learned today...

[igo4bmx]

How Sunoco determines octane of fuel...


basically they do what they've done since the 1920's

the run the fuel in a 1 cylinder motor and advance timing until they hear knock...
thats how to measure octane!

[thewake]

There are actually two tests that they perform. One gives them the Research Octane Number and the other gives them the Motor Octane Number. These two numbers are averaged and that is what is on the pump. Both use the test engine. All the refiners follow the same procedure.

[igo4bmx]

also i hear 89 is a mix of 87 and 93 and is mixed at the pump

[sur4die]

also i hear 89 is a mix of 87 and 93 and is mixed at the pump

that is definately not true... i used to pump gas, and you definately get 3 types off the truck.

[igo4bmx]

that is definately not true... i used to pump gas, and you definately get 3 types off the truck.


it depends on the station and company. My coworker used to pump gas, and they only got delivered 87 and 93

[the mike]

Sunoco only gets two types, 94 and 87. they are mixed at the pumps. I pumped Sunoco for about 3 years, and various others for about 3.

If we ran out of 94, all we could sell was regular. Conversely if all we had was regular, all we could sell was 94.

[Little G]

I never heard that before

[Gorilla Unit 33]

Sunoco only gets two types, 94 and 87. they are mixed at the pumps. I pumped Sunoco for about 3 years, and various others for about 3.

If we ran out of 94, all we could sell was regular. Conversely if all we had was regular, all we could sell was 94.
thats weird last time i was at sunoco they had 94 93 89 and 87 i know for a fact

[the mike]

They have all 4, but 93 and 89 are blends of 94 and 87.

[Philly Boy]

So basically you guys are saying that the Sunoco 93 is mix of 87 and 94? Hmm, that's interesting. I didn't know that.

[TROLL]

while we're talking about what we've heard... i was told that if you take 93 octane and mix it evenly with 89 octane... it wont turn out to be 89 octane. its not a simple add two numbers evenly and divide in half... it takes more of the higher octane fuel to bump up the overall octane (for example it might be 3/4 93 and 1/4 89 to equal an end result of 91).
bryan

[SpendOne]

Yes that is true troll, same as of you mix race with pump. I take the number of (race octane x gallons = X) (pump octane x gallons = y) ( x+y/total number of gallons ). So say ( 110 x 5 = 550 ) ( 93 x 3 = 279 ) (550 + 279 = 829 / 8 = 103.625 octane )

[BlackBulletTSi]

Yes that is true troll, same as of you mix race with pump. I take the number of (race octane x gallons = X) (pump octane x gallons = y) ( x+y/total number of gallons ). So say ( 110 x 5 = 550 ) ( 93 x 3 = 279 ) (550 + 279 = 829 / 8 = 103.625 octane )

This is a very good formula I like!

[WhiteXFire]

Except that if you go by what Troll said, you're not doing that at all. You're doing a direct averaging of the two (5/8 of 110 octane, 3/8 of 93 octane).

Something like [ 1/(5/110 + 3/93) * 8 ] = 102.94 octane would be better, but still doesn't necessarily make sense. I assume it's simply a weighted average dependent on the octane of the gas (based on how octane is calculated).

**EDIT**
If you're crazy like me and enjoy reading scientific research papers on a subject, here's a good one: http://www.simsci-esscor.com/NR/rdonlyres/5EFC339E-98A1-4DBD-A138-BDD500C6E265/0/Ron.pdf

[WhiteXFire]

Sunoco only gets two types, 94 and 87. they are mixed at the pumps. I pumped Sunoco for about 3 years, and various others for about 3.

If we ran out of 94, all we could sell was regular. Conversely if all we had was regular, all we could sell was 94.
Is this univeral to Sunoco?? In Baltimore, for example, Sunoco sells 87, 89, 91, ultra 93 (no 94 anywhere in Baltimore). If you tell me that they get 94 delivered there and simply don't sell it, I'm going to be pissed, heh. :mad: