mac11

iTrader: (1)

not. true. at. all.

Jedi54

iTrader: (7)

91 or bust
(Shell V Power)

Spinbreakz

Im not sure if i trust putting 87 octane in an engine that calls for 91. hmmm

StealthTL

iTrader: (1)

I'm compiling a tome of myths, rumors and ancient folklore related to gasoline octane ratings -

more power with the higher octane

The higher the octane the slower the gas burns

it's just the volatiliy rating of the gasoline

the higher the number, the higher temp it requires to burn

this is cause the motor takes more detonation


......and that's just in this short thread.
Thank you for your contributions to my collection.
If your Pappy told you any others, feel free to post 'em....

S

Kane

iTrader: (1)

mac11 is right on the money...

Octane is resistance to detonation which means it is HARDER to burn (oversimplification)... therefore could leave more carbon in the engine if anything not less. Racers use 100 octane either a) run more aggressive timing; resist detonation from heat soak or b) they like to waste money.

MazdaManiac

iTrader: (3)

^^ Uh Yea sure

tajabaho1

MM, half of my college class is looking at ur avatar

MazdaManiac

iTrader: (3)

Do you get credit for that?

alnielsen

iTrader: (4)

I use 87 & 89 octane. A couple of us work for or at the oil companies. As for myself, I work at BP (IT Department).
He's had the same one for at least a day without changing it yet. It is a good one.

tajabaho1

dude, I can't even come into this thread no more, its "profane"

MazdaManiac

iTrader: (3)

Its profound.

mac11

iTrader: (1)

Lets not forget that in the past (possibly still??) some rotary race teams have used as low as 80 octange fuel. What octane the car runs on has a lot to do with how it is tuned. It's also no secret that when Scott at Mazsport tunes an int-X for an N/A application he likes/prefers/recommends to tune for 87 octane.

The octane rating has nothing to do with the quality of the gas. That has to do with the quality of the manufacturer. You can go to BP, shell, ect ect and use 87 and have MUCH better gas thatn 93 octane from Huck A Buck Gas Co.

Rotary Rasp

iTrader: (2)

I dynoed exactly the same numbers with 87 and 91. Take that you 91 lovers!

mysql101

That's still an incorrect way to describe it.

The gas still burns just as easily. What it's resisting is predetonation from compression.

Galen Darkmoon

[QUOTE=The octane rating has nothing to do with the quality of the gas. That has to do with the quality of the manufacturer. You can go to BP, shell, ect ect and use 87 and have MUCH better gas thatn 93 octane from Huck A Buck Gas Co.[/QUOTE]

YEAH What he said LOL

mac11

iTrader: (1)

I stopped in a little town in Northern Illinois a few weeks ago and "regular" was 89 midgrade was 90 and premium was 93 octane. Thats how it was at all the gas stations in town and prices were the same as everywhere else. I found it hard to believe anyone would pay the extra .10/gallon for 1 octane point but 'm sure people do if they still sell the stuff. Just thought that was a bit odd.

tajabaho1

hey rotary rasp, help, I'm stuck in UNIV 100!

Kane

iTrader: (1)

I know, mysql... but I did not want to get into flame speed, sensitivity and stability of explosives and oxidizers.... yada yada yada.

Spinbreakz

So Rotary Rasp, you run 87 on a daily basis? Do you have a 6 speed or auto? and, would it make a difference with the transmissions since the engines have different power outputs?

Kane

iTrader: (1)

Good job... but did you tune for each octane?

Kane

iTrader: (1)

I am not trying to be a dick.... but HUH? Are you reading the thread? Octane has nothing to do with power output unless you advance timing with higher octane... the gasoline itself DOES NOT affect power.

tajabaho1

i use 91 for fun

alnielsen

iTrader: (4)

The biggest difference is that some companies put more detergents, for cleaning the injectors, in the "Premium" grade fuels.
All grades use the same raw stock. Chemicals are later added to raise the octane rating.

Heres more than you ever wanted to know about gasoline octane: http://en.wikipedia.org/wiki/Octane_rating

Spinbreakz

So back to mileage. How would 87-89-91 affect mileage? as in say, all highway miles or even city driving?

dontfeedthenerd

Spinbreakz doesn't know it, but ever since he moved into my apartment complex I've been peeing in his gas tank.

Maybe that's the "decrease in mileage" you've been seeing lately.