octane ratings

Post by **IvoryJ30t** » Fri Feb 13, 2004 9:18 am

while i was searching through one of the skyline forums, i figured out why motors over here dyno higher than in australia/UK/NZ.

even though there gasoline is rated at 98 octane for premium, there rating that gasoline on the RON scale. anyone thats looked at the yellow stickers on the gas pump has noticed "minimum octane rating using R+M/2 method"

in america, the octane is rated using the average of both rating systems, "research octane number" and "motor octane number".

well, it just so happens that there "98" octane premium has a MON rating of 84.

that makes their "98" octane gas rate a 91 according to our system.

i just ran across that they used the RON number, and not the average. i always wondered why we produce better dyno numbers here than they do over there.

Post by **PROJECTRB240SX** » Fri Feb 13, 2004 9:18 am

OUR GAS IS STILL PISS POOR. JAPANESE GAS IS ALMOST 100 OCTANE WHICH LETS THEM RUN 10.5 OR EVEN 11 TO 1 COMPRESSION ON THERE STOCK VEHICLES.

Post by **IvoryJ30t** » Fri Feb 13, 2004 9:18 am

yeah, i think the japanese gas is 100 MON, which would be roughly equvalent to us having 112 at the pump.

Post by **SeVa-S13** » Fri Feb 13, 2004 9:18 am

Holy moses, how many first-borns does that cost a gallon?

Post by **IvoryJ30t** » Fri Feb 13, 2004 9:18 am

well, im on the east coast, so i have 93.

for some wacky reason sunoco stopped selling 94 octane over here. i hope its just the one closest to me, i havent stopped at other stations to see if its all sunoco stations.

Post by **Tastyratz** » Fri Feb 13, 2004 9:18 am

im in mass and i still have access to 94 octane wherever i go :ylsuper so rb25 here i come!

Post by **93RPS13** » Fri Feb 13, 2004 9:18 am

at sunoco???

Post by **PROJECTRB240SX** » Fri Feb 13, 2004 9:18 am

All I get is either 91 or go to a special place and spen $4 a gallon for 104.

Post by **IvoryJ30t** » Fri Feb 13, 2004 9:18 am

i usually go to exxon [93] and all the sunoco stations had 94 octane, but the one that i used to go to stopped selling it. im curious if its just that station, or all the sunoco stations around here. just not curious enough to actually stop at another one and find out.

Post by **AREITU** » Fri Feb 13, 2004 9:18 am

You could use Toluene or Xylene to bump octane up on your car a bit if you're a tad paranoid about it. The Japanese Altezza with the BEAMS 3S-GE has a 12.0:1 compression ratio.

Post by **74260zt** » Fri Feb 13, 2004 9:18 am

I use Tolulene at 2gal to 15 gal of 93oct gas in my 8:5 to 1 turbo L6.At 18 lbs of boost, I will ping with out it. It not only stops the detonation, it feels more responsive.

If you want the low down on Tolulene, *** READ THIS ***

Post by **JonPowell** » Fri Feb 13, 2004 9:18 am

Sunoco stopped the 94 up here in Albany also, those bastards.

Post by **Tastyratz** » Fri Feb 13, 2004 9:18 am

well over in mass sunoco still has 94 which is nice...

Post by **93RPS13** » Fri Feb 13, 2004 9:18 am

my nearest sunoco dont got 94 that sux but then agian i dont have a car...haha

Post by **rudeboy** » Fri Feb 13, 2004 9:18 am

i've only seen 94 once over here, but there is tons of 93

Post by **Tastyratz** » Fri Feb 13, 2004 9:18 am

i could cry... i was wrong. they dont have 94 around here any more. i talked to the guy at a sunoco station and he told me the reason they dont have it is because of the epa or something. so in other words, it wasnt great on emissions..... :-(

Post by **Demonic240** » Fri Feb 13, 2004 9:18 am

most of the sunoco's here have the 93, but now als have 100 but the 100 is 3.99 per gallon.

Post by **S13Sil-line** » Fri Feb 13, 2004 9:18 am

One over here at 110

Post by **NISMO_RB25** » Fri Feb 13, 2004 9:18 am

I hate you guys...I would gladly pay $4/gallon for 100.

Post by **wga240** » Fri Feb 13, 2004 9:18 am

I bought a 5 gallon drum of Toluene today from my local auto painting store for $32. Not a bad price, considering last time I bought some it was from Sherwin-Williams at about $8 per gallon. I'm gonna play with it a bit and see if I can feel any difference.

Post by **93RPS13** » Fri Feb 13, 2004 9:18 am

did they ask alot of question when you bought it

Post by **wga240** » Fri Feb 13, 2004 9:18 am

Nope, she didn't ask me anything. I even asked when they'd get some more in since this was their last 5 gallon container and she said by tomorrow they'd be restocked

Post by **93RPS13** » Fri Feb 13, 2004 9:18 am

nice and this is at any paint store right??

Post by **wga240** » Fri Feb 13, 2004 9:18 am

I dunno about any paint store, but the only 2 in town had it. You just have to make sure it's straight toluene and not mixed with other chemicals. If the container actually says Toluene on it then it should be just Toluene, but read all the labels anyway to make sure.

Post by **WDRacing** » Fri Feb 13, 2004 9:18 am

I get my Toulene from Ace Hardware, been using alcohol or toulene for the last 4 years now. I use Toulene as a additive and alcohol directly injected. But I'm about to switch to a direct Toulene injection. The F1 cars ran almost straight toulene, thats how they ran 50-60 psi of boost without detonation.

I recommend atleast trying Toulene additive. I've gone with as much as 1gal Toulene to 5 gal of 91 pump. she will run worse of of boost do to the lack ignition, atleast mine did. But with the higher cylinder pressures, you'll have plenty of spark power.

WD

Post by **S13Sil-line** » Fri Feb 13, 2004 9:18 am

So does that change the number of the octane rating??? If so what would be t he octane rating for 1 gallon of toulene for every 5 of 90-91 octane gasoline. Actually if its possible can you do the ratios? Thanks

87*189*191*1

Post by **wga240** » Fri Feb 13, 2004 9:18 am

It's just a simple average of the two...ie1 gallon toluene + 5 gallons 87 = (114*1 + 87*5)/6 = 91.5

(114*1 + 89*5)/6 = 93.2

(114*1 + 91*5)/6 = 94.8

I should also add that if you want to try Toluene, don't start at 1 gallon for every 5 of pump gas. Start with 1 every 10 or 1 every 15 and gradually increase it from there. If at any point you can't tell any difference from adding a higher amount, then you probably shouldn't add a higher amount

Post by **Tastyratz** » Fri Feb 13, 2004 9:18 am

now i dont know the exact #, but i believe toluene has an effective octane of 114 or 117. do the percentages. i wouldnt recommend running a toluene/gas mix of more than 10% on a daily driver however. alcohol/water injection is very much the way to go, wd is on the right track. i plan on running a tuluene mixture and water injection setup with the rb.

Post by **xjon** » Fri Feb 13, 2004 9:18 am

I was going with alcohol injection until I read this post. Now I will start with just toluene. Reason being is I only have access to 91 octane. All I want to do now is just use the proper octane rating my engine recommends (rb25det) for stock boost.

BTW what is the recommended octane for the rb25?

Post by **S13Sil-line** » Fri Feb 13, 2004 9:18 am

Ok so on a stock RB25 what ratio would you recommend?

octane ratings

octane ratings

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