Octane summed up

General engine questions/issues that aren't specific to the other categories
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Octane summed up

By VegasCivic
- Mon May 12, 2008 10:57 pm #54935 Before I go crazy hearing another person say that 91 octane will make your car faster than 89 or 87 etc etc and race gas is the sauce. Let me inform :hehe:

NOT HOW IT WORKS. Octane isnt the measure of power, or its combustability rather the ability not to blow up. Wierd huh. Think on the lines of Detonation :D

Nobody likes detonation.

This is why you see high performance vehicles use higher octane fuel. Not for power but to not grenade.

Yes you may feel more "power" when you have a higher octane. And less when its lower. When it is higher there is less ping/knock/detonation therefore more power not wasted.

Lower octanes may allow some detonation or when equiped with a knock sensor retard the timing, so the knocks never happen. This retardation is the power "loss" or "gain" that you feel

If you feel the difference it is most likey because your being retarded. :lol: :lol: :lol: get it? :P

I kinda regurgitated this article from somewhere...its been a really long time since i read it but i never forgot it. Some tuner magazine. I just covered the basics, but after hearing someone talk about how it makes more power i about keeled over.
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By ChicagoMike
- Mon May 12, 2008 11:20 pm #54939 Good info. :thumb:
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By LowTEC-Derbo
- Tue May 13, 2008 12:24 am #54942 a good note is a car will only be as good as the tune for the fuel. Adding 100 octane fuel to your car will not make it better unless the computer knows it is 100octane fuel and tuned for such a high octane.


Octane is a measure of how well fuel can be compressed before it ignites spontaneously. High performance engines run higher compression require higher compressible fuel. This is where higher octane comes to play to help the motor from detonation.



There was an article years ago i forget which magazine but they did dyno tests on different octanes to see what would yield better results. A few cars gain hp while the honda accord (98 ones) actually lost power using 93 octane.

I would run the required octane from manufacturer unless you decide to tune your car to a specific octane.
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By VegasCivic
- Tue May 13, 2008 2:50 am #54949 The article i was learned this from is "Burn, Baby, BURN!- Drew Hardin from Superstreet june 2005. =]
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By CivicTypeR
- Tue May 13, 2008 10:33 am #55008
ChicagoMike wrote:Good info. :thumb:


X2 :thumb:
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By Bouli
- Tue May 13, 2008 1:40 pm #55025 I always put in 98 octane in the B16, it runs beautifull on that.

And the action radius is bigger so i can run a few more miles, then when i put in 95 octane gasoline.
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By Gorveatt
- Tue May 13, 2008 1:45 pm #55027 My car is rated to only need 87, but i find it just runs better on 89, less pining and what not.
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By Civic_HatchSI
- Tue May 13, 2008 4:50 pm #55048
Bouli wrote:I always put in 98 octane in the B16, it runs beautifull on that.

And the action radius is bigger so i can run a few more miles, then when i put in 95 octane gasoline.


you lucky you can buy 98 octane all we can get is 91 :0(
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By VegasCivic
- Tue May 13, 2008 6:31 pm #55064
Gorveatt wrote:My car is rated to only need 87, but i find it just runs better on 89, less pining and what not.


Exactly. :woot: It runs better not because of the gas, but because the lack of Fkcu ups inside the engine :thumb:
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By stefan
- Sat May 24, 2008 2:03 am #56443
JDM-Chick wrote:
Bouli wrote:I always put in 98 octane in the B16, it runs beautifull on that.

And the action radius is bigger so i can run a few more miles, then when i put in 95 octane gasoline.


you lucky you can buy 98 octane all we can get is 91 :0(


We have Euro 95 and Super (aka Superplus) 98.
Just filled up the car with 98, at € 1.66 per liter... in US Dollars; $ 2.62 per liter, I can't keep the English and American gallons apart, but afaik 1 gallon = 3.7 liters.
So $ 9,69 per gallon.

Ow, and a pack of 25 Chesterfield cigarettes; € 5,- or $ 7.88.

And then there are people who are baffled that I say; MOTHERFUCK EUROPE... stupid people
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By Graham
- Sat May 24, 2008 11:20 am #56458 You guys only get 91 octane? :o

Even the normal stuff here is 95! You can get 98 or theres also 101 stuff here too but its stupid expensive :lol:
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By CivicTypeR
- Sat May 24, 2008 10:07 pm #56481 98 in my tank :) 101 is a rip off G.
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By suspendedHatch
- Mon May 26, 2008 5:47 pm #56660 Only 96+ aka OBD2 cars have knock sensors. The knock sensor is used to PULL timing, not advance it. So if the base calibration is tuned for 87 octane, you wont make any gains running higher octane. The only difference is that a knock controlled calibration will be a bit more aggressive with timing compared to an OBD1 calibration. The confusing part however is that the OBD2 motors (D series at least) have less timing advance because the heads are more efficient so it's not needed.

Also realize that Octane is calculated differently in the US than where you guys are from. Your 95 Octane is not the same as our 95 Octane. Ours is calculated as a minimum, while yours is calculated as an average.

If the manufacturer tells you to run 87, and you get better performance on higher octane, then you have a problem. 1) you're buying bad gas 2) your base ignition timing is off 3) your motor is in poor condition 4) you're not using the correct spark plugs 5) you're burning oil 6) you have a lot of blowby cycling through your PCV system 6) you're not accurately measuring "better performance" 7) etc
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