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Anyone runs your WRX with 87 Octane?
If so, will it harm the engine or has dramatic effect on performance? Well, I know the owners manual states 91. Just curious.
 

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IMHO I think it would. I put 87 in my 98 Dodge ram "being cheap for the 13mpg it got" and a few weeks later a CEL and engine knock..had to replace the engine..Somehow ended up runnin on 7cyl only and the recommended was only 89..so pay n ow or pay more later
 

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salvagedwrx said:
Anyone runs your WRX with 87 Octane?
If so, will it harm the engine or has dramatic effect on performance? Well, I know the owners manual states 91. Just curious.
Don't do it, you should be giving your baby the best stuff available.

In Australia we have 98 RON fuel, its just so much better for the car.
 

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With my past cars it never made a difference, but when i was low on $$ one day, i threw in a tank of 89 into my WRX and after about a day it ran like total crap. It had no top end like it was being restricted in some way and took off horrible also. I called Smart Service in seattle and told them my situation and the first question the asked was,"you put 89 octane in right?" They sad to run the tank and fill up w/ super. I did and about a day later w/ the super in the tank, my car was back to normal. Seems like all WRX's are different, but thats just my situation. Shaun
 

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The fuel thing has been covered. It really helps to know "WHY?" Here's a lay-person (like myself) take on it:

There's a misconception that expensive cars need expensive fuel. That's not true. Octane is mainly anti-knock properties. Knock is what happens when fuel detonates pre-maturely. There is a higher likelihood of this happening when either the temps in the cylinder head is very hot and/or the compression (or pressure in the cylinder head) is very high. Basically it's so freak'n hot in there the fuel ignites even without the sparkplug. The amount of damage this cause depends on severity of the combustion and the piston position when it happens...so too much knock means better chances of Real bad damage.

So, turbo cars get VERY hot and it's forced induced (more pressure), so that's why we need high octane for the engine to run ideally and safely. If low octane is used, the ecu will "slow" everything down (pull timing)to reduce temps, which will make the car drive like arse...

That's why for most cars, it makes no diff, but for turbos and high compression engines, it makes a significant diff.

As a noob, it took awhile to figure all that out. I hope I did a good job of explaining it.
 

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a post a did awhile back that explains the difference between RON and MOV octane levels
click me
also some usefull information about increasing octane with household items ??safely??

- M a t t -
 

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If you have no engine mods and you run 87 the knock sensor will tell the ECU to retard timing if there is a problem. You won't make as much power but it will run fine.
 

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89

My wife borrowed the car the other day.:rolleyes: When she returned, she told me that she had topped it off:) but that she wasn't sure what type of gas she was supposed to use.:mad: She told me that she put 89 in "just to be safe".:eek:

I wasn't sure what this would do to the car,:confused: but I figured if nothing else it would be a good exuse to try out some of that Octane Booster.:p I picked some up at the store and put it in the tank before I left the parking lot.:cool: I then took it for a short drive to "mix it in w/ the gas".:D I didn't notice any ill effects from the low octane gas on my way to the store, but I didn't drive it that hard either.

When I got home I figured it wouldn't hurt to reset the ECU so I disconnected the negetive batt. cable and stood on the brake for a few seconds. Lost my stereo settings.:(

The Box tells me that I can't use any more smilie faces in my post. Too Many.:eek:

Later, T.J.
 

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I just had some great luck with 1.5 gallons of toluene in a 1/2 tank of 92 last night...

My rough calculations put the final octane of the swill at ~94... Picked up a tenth in the 1/4 and almost 1 full mph...
 
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