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What Octane number do you use inyour gas tank?

  • 91-93, Yea Baby!!

    Votes: 111 36.5%
  • 89, does the job, no complaints.

    Votes: 64 21.1%
  • 87, I'm poor, only wish i could use the high stuff.

    Votes: 129 42.4%

  • Total voters
    304
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Discussion Starter #2
I'll start, I use 91-93 Octane, and Texaco (now known as Shell) and 76 seem to be the better grade of gas over here in Wenatchee, Washington. But I am thinking of going down to the 89 Octane, just to see if I can notice a difference and save a couple bucks.
 

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89 usually.. 93 or 94 if i'm feeling lucky and rich.. And if i'm going to race.

Sunoco all the way. BP licks my nuts :flame:
 

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2001 Subaru 2.5 RS Coupe
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478 Posts
i use to put 91 in my car all the time, however since gas has gone up I decided to give 89 a try. So far the car seems to be running a little better on 89. hopefully the I'll get more miles out of a tank now. I'll let you guys now what happens.
 

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Premium Member
MY98 2.5RS Coupe Brilliant Red
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87 Octane, as liigod stated above, it's what the stock ECU requires. It is what the naturally aspirated engines are tuned for.

Adding higher octane fuel to a NA car does nothing. The higher octane fuels are for the higher performance engines. Engines that are turboed and super charged require the higher octane fuel as it burns slower. This is necessary due to the higher temperatures inside the engine due to boosting.

I fail to see any benefit from adding higher octane fuel.

And I'm not poor for putting in 87, I'm following directions.

Fuel Octane Ratings
What Octane Should I Use?
Howstuffworks article on "Octane"
Google Search on "Octane Rating"

AJ
 

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2006 Pontiac GTO 6spd
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squared away said:
And I'm not poor for putting in 87, I'm following directions.

AJ
You beat me to it, but ya. The car runs worse with higher octane in my experience. I get crap from people sometimes, but I don't care as they really don't know what they are talking about. I use Shell for the most part. Chevron is better, but the cesspool of the midwest fails to get it.

JC
 

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Premium Member
MY98 2.5RS Coupe Brilliant Red
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880 Posts
And for brands, I try to stick to the following

Mobile
Amoco
Citgo
Texaco

I don't know why, it's just been a thing with my family to go to a few specific gas stations. Makes it easy.

And I've have an ongoing track of my MPG and other neat figures I can gather between fill-ups.

AJ
 

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teh member
2000 GC8 (GM6) RS Silverthorn
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On special occasions my car gets higher grade however the normal is 89 since yes prices are very high and the highest grade just doesn't seem worth it. The manual I believe doesn't even say for 89 so I'm already going a step up, I just don't see the purpose for that one more step. As far as brands usally Safeway gas since it normally the cheapest and I know for a fact it's just as good as most all the stations around here.
 

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2010 Impreza 2.5i 5-door, 5-sp
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squared away said:
...I fail to see any benefit from adding higher octane fuel.
And I'm not poor for putting in 87, I'm following directions...
Yeah, exactly! Being poor has nothing to do with it.
If my RS was supposed to run on 91, then that's what I would use. I don't care about the cost. My previous car was a 1997 Prelude w/ VTEC. The manual called for 91 octane so that's what I used. My RS is designed to run on 87 octane so that's what I use. I don't even look at the gas prices. I just swipe my gas card and fill the car with the proper octane fuel.
Unless your RS is turbocharged or supercharged or you are running agressive tuning like advanced timing or something, using anything higher than 87 octane is a waste of money.
 

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I run Shell Optimax (98 octane)...
Good stuff...

Which according to the dealer, and everyone I've spoken to, is the Best petrol to use in any car in AU... (Plus it took my petrol consumption from 10 L/100km to 8.5 L/100km)
 

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13 Years of RS
2005 Toyota Corolla :(
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I usually use 87, but sometimes I use the 91. I have the ProECM in my car, and it's supposed to be able to take advantage of higher octane by advancing the timing. Right now, I have a little spreadsheet on my PDA, and I'm keping track of MPG, cost/mile, and what octane has been used. I'm going to use 87 for the next several fill-ups, and see what happens. Then I'm going to use 91 for the next bunch (so the ECU has time to learn the difference between the two), and see if there's a difference, and whether or not the difference is big enough to make it economically feasible. I'll try to keep you all updated, if I can remember. Oh, and I pretty much only use Shell.
 

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Discussion Starter #16
rsowell28 said:
Yeah, exactly! Being poor has nothing to do with it.
If my RS was supposed to run on 91, then that's what I would use. I don't care about the cost. My previous car was a 1997 Prelude w/ VTEC. The manual called for 91 octane so that's what I used. My RS is designed to run on 87 octane so that's what I use. I don't even look at the gas prices. I just swipe my gas card and fill the car with the proper octane fuel.
Unless your RS is turbocharged or supercharged or you are running agressive tuning like advanced timing or something, using anything higher than 87 octane is a waste of money.
Waste of money....A waste of money is using 87 'cause you probably haven't taken the time and used the 91 for several tank fulls and you dont know the difference between your car running better and smoother with 91compared to it running crappy. If you havent used the 91 or even 89 for a couple of tanks (more then a week) and only use the 87, you wont know the difference. So spending an extra $0.20 on gas really does make a difference.

UNLESS: You have compared the Octanes and the 87 does make your car run better...but i doubt it.

You dont skimp and use cheap parts when it comes to other important parts of your car do you, then why skimp on gas?
 

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2010 Impreza 2.5i 5-door, 5-sp
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:confused: I thought that if you were running the ProECM, that you had to use 91 octane or higher because it advances the timing. I don't have one though so I don't really know. Could somebody who has one please clue me in? :burnout:
 

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Discussion Starter #18
rsowell28 said:
:confused: I thought that if you were running the ProECM, that you had to use 91 octane or higher because it advances the timing. I don't have one though so I don't really know. Could somebody who has one please clue me in? :burnout:
Sorry dude, Id didnt mean to confuse you. I dont know what you should use when running a ProECM, but I do know that using the higher octane does make your car run better. NOT saying this for everyone, but it looks like the majority say the prefer 89 or above.
 

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2010 Impreza 2.5i 5-door, 5-sp
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CWC.02 said:
Waste of money....A waste of money is using 87 'cause you probably haven't taken the time and used the 91 for several tank fulls and you dont know the difference between your car running better and smoother with 91compared to it running crappy. If you havent used the 91 or even 89 for a couple of tanks (more then a week) and only use the 87, you wont know the difference. So spending an extra $0.20 on gas really does make a difference.

UNLESS: You have compared the Octanes and the 87 does make your car run better...but i doubt it.

You dont skimp and use cheap parts when it comes to other important parts of your car do you, then why skimp on gas?
I did try 91. I ran 91 for the first month that I had my RS. Then I realized that 87 would probably work better so I switched to that. On 87 my car runs the same as it does on 91 except it gets better mileage and 87 is cheaper. My car is n/a so I don't need a high octane fuel and the car is designed for 87. 91 will work fine but it's more expensive and the mileage suffers.
 

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2010 Impreza 2.5i 5-door, 5-sp
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CWC.02 said:
Sorry dude, Id didnt mean to confuse you. I dont know what you should use when running a ProECM, but I do know that using the higher octane does make your car run better. NOT saying this for everyone, but it looks like the majority say the prefer 89 or above.
Do you have a ProECM? Maybe that's why your car runs better with 91. :confused:
 
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