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View Full Version : Minimum octane level? fuel comparison question


iwishiwas-all*
03-22-2009, 09:13 PM
Hey, In my IC engines class we were going over the various molecular structures of gasoline available to the public, and various standards and such.
Our teacher brought up Vapor pressure and Minimum Octane level as the two regulated parts of gas.
This got me thinking, I know im not the first, but here it goes.
Gas companies set MINIMUM octane levels, lets say for premium on the east coast, 93octane on the (R+M)/2 method.


Which gas companies have the highest levels above this minimum??

Lets say Shell mixes their shit at 94.5 octane just to suffice for regulations, while marathon may just use a bare minimum of 93.23 or whatever.

Any information on which gas has the most octane, this can be quite beneficial for the combating of knock for all you high hp guys. As well as this stock Sr's may respond better to the highest levels because it mimics the gas used in japan.

Also, all gas is not created equal. there are a bazillion different kinds, its almost hilarious.

Any input to this?
Lets find the most bomb gas for our money hahah.

slider2828
03-22-2009, 09:39 PM
Here is from my experience... All cali 91 gas is pretty crappy. There is just so much crap in it, it makes my SR run blah.... On my car, I get a black rear bumper like within a week... I have the luxury of a VP Racing gas station that has 93 and 100 on the pump. When I fill up 93 or 100 I NEVER get any sign of color on my bumper at all and runs stronger and quiter. This is just what I have observed... in terms of science... I dunno

lflkajfj12123
03-22-2009, 09:50 PM
the bp and shell plants are right down the street from me

should i go ask? haha

mondojackal
03-22-2009, 09:58 PM
Yes. My car runs noticeably better with Shell or BP gas. I refuse to use Citgo/7-11/etc.

iwishiwas-all*
03-22-2009, 10:00 PM
the bp and shell plants are right down the street from me

should i go ask? haha

why not, i would love to see,
there is soo much that goes into it its scary, im gonna scan a handout i got about samples and chemical concentration in fuel its very interesting

lflkajfj12123
03-22-2009, 10:12 PM
Yes. My car runs noticeably better with Shell or BP gas. I refuse to use Citgo/7-11/etc.

shrug i just fill up at meijer gas station (midwest thing) its right next to my house

i searched a bit i don't know who supplies their gas for them

maybe they don't want to give that information out

Kaifd3s
03-23-2009, 08:21 AM
I just fill up with Sunoco by my job. I've heard all the gas in Florida come from the same tankers, and that there is no difference. I do however ALWAYS run 93, I dont care about brand anymore.

drifter_for_life06
03-23-2009, 09:18 AM
i run shell 93 like its nobodies business. However, I PREFER Sunoco due to i get 2mpg better with sunoco over shell. Plus a local Sunoco station has 94 octane and they used to have GT100 race gas at the pump...but got rid of that when gas prices sky-rocketed

juiced305diesel
03-23-2009, 09:27 AM
The real big difference among gas companys is the additives that they use. Being half a point higher in terms of octane wont really due much for knock protection or performance. My only advice is once you start making power you could switch over and get tuned on E85 you have three gasoline stations that carry E85 right down the street from you. R@mon just made 705RWHP on E85 he maxed out the 1600CC. We just installed Mikes Billet PTE 6765 were hoping to get in the 7???.RWHP The issue with mike is his 1600CC and that he went with the regular stlye arp head bolts instead of the half inch headstuds so we got to stick around 40 PSI.

drifter_for_life06
03-23-2009, 10:14 AM
no e85 love here in PA :(

jskateborders
03-23-2009, 12:41 PM
Lets find the most bomb gas for our money hahah.
E85. Done and Done (if its available in your region)

dorkidori_s13
03-23-2009, 12:45 PM
E85. Done and Done (if its available in your region)


2nd...105 octane race gas for 2 bux a gallon ;) god i love my standalone

iwishiwas-all*
03-23-2009, 01:17 PM
http://i3.photobucket.com/albums/y75/Gabedm/photo-2.jpg

to further the point that all gas is not created equally, check out this handout i got.
each column (although the top got cut off) is a different gas sample from an entirely different station. the numbers are diff %'s of each compound in the fuel, and a few are labeled as to their purpose.
Its funny cause some gasses such as Methanol-to-gasoline behave like gas (w/ respect to vap press and octane #) but are 10000% different from every kind of conventional gas out there.
I got that class at 5 today so im gonna ask him about e85, he has dabbled on it saying the octane levels are superb for knock protection, but their are some drawbacks.
I can explain the paper a bit more if u guys like, I should know mmost of the info u need on it.

Bigsyke
03-24-2009, 01:20 AM
I banged a chick who's family owned a gas station,

- Some companies like holliday and SA inject water to their gas

Koopa Troopa
03-24-2009, 01:29 AM
As well as this stock Sr's may respond better to the highest levels because it mimics the gas used in japan.


Japan uses RON not ^2 so the ratings are different.