Accidentally put 87 Octane on 13 wrx.

[Borgeeulol]

I went ahead to Exxon gas station to fill up my tank this morning right after work. I asked the guy to fill up 93 octane in my car and proceed to clean my windshield. After few minutes, I checked out the octane rating on the pump which I always do during fill ups. My eyes popped when i saw it was 87 and ran toward the pump to stop it. It was almost filled (8.3 gallons 87oct) which has still 1/4 remaining left and proceed to fill up the remaining with 93 oct (4.5 gallons). Is it ok to drive the car until the gas reach to 1/4 tank empty and fill it back to 93oct? Does it damage the engine on low octane? Need your advice?

Thanks

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[02nismokiller]

No your not gonna damage nothing. Just drive the car, don't be beating on it or build any boost. The owners manual states you can put 87oct for short periods of time. Your fine, don't sweat it

[Cathexis]

Or toss in a can of octane booster and fill the rest of the way with 87 or 89.

[Borgeeulol]

Originally Posted by 02nismokiller

No your not gonna damage nothing. Just drive the car, don't be beating on it or build any boost. The owners manual states you can put 87oct for short periods of time. Your fine, don't sweat it

Drove home at least 50mph on the highway and under boost like a granny. Hopefully I could fill her up this weekend. Lesson learned. Thank you!

[Borgeeulol]

Originally Posted by Cathexis

Or toss in a can of octane booster and fill the rest of the way with 87 or 89.

Definitely going to autozone after the morning rush. Thanks!

[point78]

Unless they have a can of something like Torco octane booster, or Toluline, don't bother.

Better to find a place that sells 100octane gas and dump a few gallons in.

[JoshP]

RIP. Just kidding you'll be fine.

[Blackfin]

If you're running a tune (e.g.Cobb Stg 1 or 2) then go back to stock for this tank.

Otherwise, just take it easy. Be aware that it will be a couple of tankfuls of premium before the octane in the tank is really 93 because there will be a few gallons of 87 diluting things even when the gauge reads near 'E'.

[liltoua]

throw some race gas in there! Even it out

[JimmyBoyWRX]

Originally Posted by Blackfin

If you're running a tune (e.g.Cobb Stg 1 or 2) then go back to stock for this tank.

Otherwise, just take it easy. Be aware that it will be a couple of tankfuls of premium before the octane in the tank is really 93 because there will be a few gallons of 87 diluting things even when the gauge reads near 'E'.

Better to stay away from the already knocky stock tune.

If he does have an AP then use it to pull a couple of degrees of timing. It has that option for this exact reason.

Plug it into your car and then scroll through the adjustment menu. You will see it.

[trev762]

Originally Posted by liltoua

throw some race gas in there! Even it out

Not a good idea to do this as most race gas is oxygenated and will not mix with regular gas.

[trev762]

Originally Posted by JimmyBoyWRX

Better to stay away from the already knocky stock tune.

If he does have an AP then use it to pull a couple of degrees of timing. It has that option for this exact reason.

Plug it into your car and then scroll through the adjustment menu. You will see it.

^^^This

[trev762]

Originally Posted by Borgeeulol

Drove home at least 50mph on the highway and under boost like a granny. Hopefully I could fill her up this weekend. Lesson learned. Thank you!

I would have taught them a lesson and wouldn't have paid for the tank of useless 87 octane they put in your car.

[rosedaleny806]

had to do it twice when hurricane sandy hit and no 91 or 93 was available, no issues. just take it easy

[LIChuck]

Just add three gallons of e-85 as soon as you can fit it in the tank and you will be fine. E-85 is over 100 octane.

[jrodm12]

If u really want to pump old gas out. Put it in test mode and disconnect fuel supply line. Connect hose to it and put in gas can. Turn ignition on and pump will turn on and off.

[Razgeiz]

Originally Posted by LIChuck

Just add three gallons of e-85 as soon as you can fit it in the tank and you will be fine. E-85 is over 100 octane.

This is a horrible idea.

[trife86]

Originally Posted by trev762

^^^This

And how much timing would you suggest to knock dowb

[trev762]

Originally Posted by trife86

And how much timing would you suggest to knock dowb

I'd say a couple of degrees just to be on the safe side but wouldn't consider this a fix to go wot though.

[Borgeeulol]

Thanks guys! Appreciated all the feed backs. Hopefully within few days, i'll be filling her up back to 93 octane. Driving very slow and under boost for the remainder of the tank. Thanks again!

Fonzee

[JimmyBoyWRX]

Originally Posted by trife86

And how much timing would you suggest to knock dowb

3 degrees should be fine and no agressive driving.

Based on most timing corrections I see on people running 87 by accident seem to be around 2.8 degrees

[subezero]

Originally Posted by LIChuck

Just add three gallons of e-85 as soon as you can fit it in the tank and you will be fine. E-85 is over 100 octane.

Do us a favor and never post again. Thanks.

[LIChuck]

You guys don't know what you are talking about, E85 increases the overall octane. You don't need to pull timing when you add octane, the question is how far can you push timing.

E85 is 85% alcohol so in three gallons you are adding 2.55 gallons of alcohol. That will be about 20% of the fuel tank capacity. You can run a 20% blend on the stock injectors. I did this for months while data logging without any problem.

Not only will it not do harm, it will give you better performance. If you do it long term, run data logs so you can make sure your set up can run the blend without a problem.

Flame all you want but do the math for yourself and figure out what the octane in the tank will be after adding 3 gallons of E85.

Use the search feature and you will be enlightened! Then try it and smile at the resulting power increase while saving money, running cooler combustion temperatures and keeping your fuel system clean and dry.

Subezero I will do you a favor and keep posting in order to do what these forums are intended to do; provide helpful information and stamp out ignorance.

[JimmyBoyWRX]

Originally Posted by LIChuck

You guys don't know what you are talking about, E85 increases the overall octane. You don't need to pull timing when you add octane, the question is how far can you push timing.

E85 is 85% alcohol so in three gallons you are adding 2.55 gallons of alcohol. That will be about 20% of the fuel tank capacity. You can run a 20% blend on the stock injectors. I did this for months while data logging without any problem.

Not only will it not do harm, it will give you better performance. If you do it long term, run data logs so you can make sure your set up can run the blend without a problem.

Flame all you want but do the math for yourself and figure out what the octane in the tank will be after adding 3 gallons of E85.

Use the search feature and you will be enlightened! Then try it and smile at the resulting power increase while saving money, running cooler combustion temperatures and keeping your fuel system clean and dry.

Subezero I will do you a favor and keep posting in order to do what these forums are intended to do; provide helpful information and stamp out ignorance.

You will get ZERO increase in power by adding some e85 as you are on a tune meant for pump gas. Your timing and boost levels will be the same with a fuel with less energy content then gas.

You will save ZERO dollars using e85 in this manner if anything the opposite is true. Unless you are picking the stuff up at 2 bucks a gallon.

Anything over e20 and you are risking maxing out your fuel trims and injectors.

[LIChuck]

You raise valid concerns which I will address. Read the E85 thread if you want some very detailed discussions.

You would get zero increase IF your car had a static tune and the computer couldn't learn. However, the computer does learn and adjust for the higher energy content and higher octane of the E85. It adjusts the injector duty cycle and advances the timing. So alcohol does increase power as long as the injectors can deliver the fuel and maintain your fuel trims which is why I said to data log. All you need to watch are your injector duty cycles but checking the AFR is prudent.

Where I am the combination of 87 pump gas and E85 is cheaper than 91 and certainly 93. This might not be true everywhere. Surprisingly, it doesn't negatively effect your gas mileage by as much as you would think.

I stop mixing 87 and E85 because the station that has E85 sold me contaminated 87 and I was more concerned about the bad 87 octane than the E85.

E20 is correct. Three (3) gallons is the max I went to and that is E20. Assuming a 15 gallon tank, 3/15=0.20 or 20%.(Assuming E85 is 100% alcohol which it isn't so this give you a little head room)

Again, read the E85 thread and do some research. This is not a bad option if you can't get 93 or get 87 by mistake and can get E85.