what octane

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what octane

By beerys95lx
- Tue Jan 04, 2011 5:35 pm #231407 do you have to run 93 octane gas if you have 11:1 compression?
if not what would be a save octane to run?
it would be a d15b7 with a y8 head on it.
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By teal_dx
- Tue Jan 04, 2011 5:37 pm #231409 with 11:1 I would not go lower than 93.

edit: I ran a d15b7 mini-me w/ d16y8 head and I thought my CR was more like 10.5:1. what head gasket are you using?
Last edited by teal_dx on Wed Jan 05, 2011 5:30 am, edited 1 time in total.
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By beerys95lx
- Wed Jan 05, 2011 5:05 am #231509 the one thats 0.025in thick.

i also have 212000 miles on the car would that be a problem?
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By Ecc0
- Wed Jan 05, 2011 11:58 am #231535 I always find this funny that out there you guys run 93 octane.

The lowest we have is 95 and I run 99 all the time though I pay a shed load more for it, thanks to the tax man.
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By eg84dr
- Wed Jan 05, 2011 4:40 pm #231570
teal_dx wrote:I remember hearing that we rate our octane differently than you guys do over there. I forget the reasoning why... :?

diffrent aditives i believe :?
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By Ecc0
- Wed Jan 05, 2011 10:21 pm #231631 I know that different mixes are used for summer and winter due to the changes in temp so I would guess the same would be for fuel over your side of the pond to deal with climet differences and temperatures
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By beerys95lx
- Thu Jan 06, 2011 11:45 pm #231817 so how high does the octane go
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By chrisscott
- Fri Jan 07, 2011 12:14 pm #231902 i heard in japan they run 101 octane, but not 100% sure
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By Eg6H2D
- Tue Jan 11, 2011 2:34 am #232572
Ecc0 wrote:I know that different mixes are used for summer and winter due to the changes in temp so I would guess the same would be for fuel over your side of the pond to deal with climet differences and temperatures


out here in Mass the fuel doesnt change. it's the same 87- 89 -91- 93 octane. the diff is in seansons changing so does the freakin price!! lol.
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By Ecc0
- Tue Jan 11, 2011 9:31 am #232622
EG6b20R wrote:
Ecc0 wrote:I know that different mixes are used for summer and winter due to the changes in temp so I would guess the same would be for fuel over your side of the pond to deal with climet differences and temperatures


out here in Mass the fuel doesnt change. it's the same 87- 89 -91- 93 octane. the diff is in seansons changing so does the freakin price!! lol.


you won't see the octane change on the board when you buy you gas but it's the mix of the fuel that is changed to allow for temp changes

We can get 95, 97, 98, 99 and soon 100 octane fuels also ours it dependant on which company you buy from

Re: what octane

By AutoXCivic
- Mon Jan 17, 2011 1:47 pm #233770
beerys95lx wrote:do you have to run 93 octane gas if you have 11:1 compression?
if not what would be a save octane to run?
it would be a d15b7 with a y8 head on it.



If you have a REALLY good tuner ... no you don't. But you should to be on the safe side. Octane only prevents detonation ... which is good. I've seen a 13.5:1 motor run on 87 octane, but that guy was a crazy good tuner. For the rest of us ... stick with higher octane fuel.
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By Ecc0
- Mon Jan 17, 2011 3:05 pm #233778
suspendedHatch wrote:
teal_dx wrote:I remember hearing that we rate our octane differently than you guys do over there. I forget the reasoning why... :?


Right. Their 95 RON is the same as our 91 AKI.

Wiki is your friend.

http://en.wikipedia.org/wiki/Octane_rating


Good find think this is the main highlight from that piece

Anti-Knock Index (AKI)
In most countries, including all of those of Australia and Europe the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Road Octane Number (RdON) or Pump Octane Number (PON).

Difference between RON and AKI
Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel. See the table in the following section for a comparison.
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