87 instead of 91

So my GF filled my tank up with 87 last night. How bad is this? I was just going to go to the local auto store and put a bunch of octane boosters in there. Would that be ok?

Oh dear!

 

I would try and drain as much out as possible.

 

If you can't do that, the octane boost may help.

 

Why don't you call the guy's at Fredbeans and ask them. You'll get a quick answer on what to do.

 

Check the Vendor forum.

 

 

Is she still your GF ?

Don't buy octane boosters, 99% of that shit is, well shit. The only good ones IIRC are Torco and Lucas. Just don't bomb the throttle till you can replace at least half a tank. Lower octane fuel will create knock, which can cause premature detonation and chip pistons. As long as you're not boosting then you'll be alright. Just shift at 3k rpm and keep in a higher gear and it'll be fine.

 

But the thing about the octane boosters is they'll say they'll boost it 6 or 8 octane or something along those lines, IIRC that 6 or 8 is actually .06 or .6 so really you won't end up any higher then 87.6. Unless like I said you use torco, I think it boosts 80 points. I know a full can in a half tank on my grand prix would put me from 92 to 100.

Just take it easy until the you use up the gas.

By easy I'm sure he means keep it out of boost.

One or two tanks of 87 won't kill your engine or cause massive detonation. Just take it easy on the car for the time being.

Is the car stock?

 

If it's stock, the ECU will compensate before bad things happen. It's not ideal, but it does happen, and OEM's are prepared to handle the occasional incorrect tank of fuel. You aren't the first, and won't be the last person who has put 87 in a car requiring a minimum of 91.

 

Just keep reminding your right foot that you have 87 in the tank, and you'll be fine.

 

If you are really worried, burn the tank down half-way or so and then find a local place that sells 100 octane from a pump. It's unleaded, and you can directly pump it into the car. You will gain some wiggle room that way.

if you have a cobb RT flash the ecomap. that will help me you in control till you burn out the fuel.

 

if you do add octane booster dont add more than one bottle. more than one bottle can acutally be more damaging (due to all the additives) then the bad gas.

Lucus Oct Booster has the best rating and reviews.

http://volvospeed.com/Reviews/octane_boosters_lucas.html

This just reminds me of every time i fill up with a girl in the car that hasnt been with me at the pimp before.. "WHY ARE YOU PUTTING IN EXPENSIVE GAS?"

 

If you're down already a bit just try and squeeze some 100 octane in like BASC5.2 said

I think this may have happened to me. Way back when I purchased my car from a dealer I recieved less than acceptable service on delivery date. Long story short I received 2 free tanks of gas. for the second tank of gas I actually drove the car to the gas station with the salesman that sold me the car (first one I did not). I had a suspision that I should verify that my lgt took 91 octane when I was getting my second tank and the salesman was ready to pump in 87 octane. He almost seemed surprised that the car took 91. That leads me to believe that the car had 87 octane in it for ~340 miles of spirited driving. And before that 1st tank of gas was empty I either became used to the power, or my car was not producing the same HP, and has not since. I am really debating taking the car to the dealer and having it looked at as I do have powertrain warranty still. Could I have damaged the engine by spirited driving through an entire tank of 87 octane or am I just crazy?

 

 

Stay out of boost and you should be fine

cypher, my buddy who's owns a machine shop that does a lot of Subaru heads for the dealers say's he thinks that a lot of the bad valves they see are from people trying to use 87 octane in a turbo engine.

Get the lucas octane booster. It will actually raise the octane level. Most of that octane booster crap is a scam. It says it'll raise it x points. What they put in the fine print is that each "point" is actually 0.1 octane. So you'd need 40 "points" to go from 87 to 91. The Lucas stuff works with whole octane points. Just get a bottle, pour it in, and drive like a normal person until you can fill up with premium.

Don't worry. Just put 93 octane when you are at half a tank you will essentially get 90 octane.

 

The owner's manual states that you can use 87 octane if 91 octane is not available. However to make sure and use 91 octane again.

my neighbour ran for 5 years in his wrx with the cheapest gas he could find .. never a problem .. and you will probably get another 100 milles or 160 km on that tank ..

Yuukkkk!!!!! Mine runs best on 98!!!!

jp 08 gtb 6mt wagon

Yuukkkk!!!!! Mine runs best on 98!!!!

jp 08 gtb 6mt wagon

 

Your 98 is like our 93.

^ Like Euclid said, jp928, there's differences in how fuel is "rated" from one area of the world to another - and that will account for the "octane" differences on the label.

 

When speaking "internationally," it's important to identify how your area, versus that of the conversation/OP, quantifies "octane rating," in order to prevent misunderstandings:

 

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

 

 

 

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Just take it easy until the you use up the gas.

 

^ Do this.

 

 

 

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If it's stock, the ECU will compensate before bad things happen. It's not ideal, but it does happen, and OEM's are prepared to handle the occasional incorrect tank of fuel. You aren't the first, and won't be the last person who has put 87 in a car requiring a minimum of 91.

 

Just keep reminding your right foot that you have 87 in the tank, and you'll be fine.

 

If you are really worried, burn the tank down half-way or so and then find a local place that sells 100 octane from a pump. It's unleaded, and you can directly pump it into the car. You will gain some wiggle room that way.

 

^ And partially, this, too - the only issue I have with this particular post is what's highlighted.

 

The problem is that the ECU is reactive, not proactive.

 

The ECU responds to ("learns") from what it perceives to be knock - and as just one knock event can, theoretically, kill the engine...well, that's leaving a bit up to chance, as that one event may just be that learned event. (On this note: if you have an aftermarket map on your ECU, Max Capacity, flash to a low-octane/low-boost map, or another map that has less aggressive timing [this would be proactive].)

 

But speaking realistically, like BAC and others here have said, unless you go around floggin' the heck out of the car, it should be just fine.

 

Like BAC said, it's happened before, it happens, and it'll happen again.

 

Just take it easy, and you'll be fine.

 

 

 

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Don't buy octane boosters, 99% of that shit is, well shit. The only good ones IIRC are Torco and Lucas. Just don't bomb the throttle till you can replace at least half a tank. Lower octane fuel will create knock, which can cause premature detonation and chip pistons. As long as you're not boosting then you'll be alright. Just shift at 3k rpm and keep in a higher gear and it'll be fine.

 

But the thing about the octane boosters is they'll say they'll boost it 6 or 8 octane or something along those lines, IIRC that 6 or 8 is actually .06 or .6 so really you won't end up any higher then 87.6. Unless like I said you use torco, I think it boosts 80 points. I know a full can in a half tank on my grand prix would put me from 92 to 100.

 

^ Just be sure to use the good stuff, like Torco, the Lucas "off-road" formula, the NOS brand "Racing" (off-road) formula, or the "Outlaw" off-road formula (REF: http://volvospeed.com/Reviews/octane_boosters.html), or even self-blend with Toluene (there are plenty of on-line resources that have ready recipes). Race-fuel, of course, is another alternative.

 

BruceBruce - just pour in a bottle, and take it easy. It's really not that bad. Once you get to half-tank, put in some premium.

 

You'll be OK.

 

The wifey did just this, a month ago, in the worst of our summer heat and mugginess, with her FXT.

 

No big deal.

Yes shes still my gf lol. I'm a stg 2 non aggressive tune by infamous. I ended up buyin the Lucas "off-road" non street legal formula and putting it in. Figured that wasnt something i wanted to cheap on so went with a trusted name lol. I've been keeping it no higher than 3k rpms and luckily work and school is all inside a city and nothing really higher than 55mph is the speed limit. Ill fill up again at half tank or so and put the 91 back in. Since that is the highest i can get around here.

Ah, you're tuned.

 

If you're keeping it out of boost, you should be just fine - but since I'm assuming you've got some sort of datalogging equipment, you might as well hook her up, take her for an easy drive, and see if anything's too out-of-whack (i.e. may then have to reflash, temporarily, to an even less aggressive map).

Good catch Allen, I didn't mean to imply that the ECU was pro-active.

 

But, that does bring up a good point. If you remain in closed-loop, the ECU should prevent bad things from happening in a nearly pro-active manner. Closed loop fuels and times based on sensory feedback, a bad event can ALMOST happen and the O2 sensor should pick it up. The ECU *SHOULD* pull timing and add fuel. Open loop is where you run into your problems.

^ Nah, not a catch, don't see it like that, please.

 

I agree, it should be *nearly* instantaneous, but then again, I'm just overly cautious. Hell, look at how LittleBlueGT blew his engine.

 

Like Rao, I never drive my LGT anymore. It's just a big paperweight!

This just reminds me of every time i fill up with a girl in the car that hasnt been with me at the pimp before...

 

 

 

Anyway - a single tank won't ruin anything as long as you take it easy.

^ Nah, not a catch, don't see it like that, please.

 

I agree, it should be *nearly* instantaneous, but then again, I'm just overly cautious. Hell, look at how LittleBlueGT blew his engine.

 

Like Rao, I never drive my LGT anymore. It's just a big paperweight!

 

Sitting on paper is actually bad for the tires. You should consider parking it on pillows.

Down or Tempurapedic?

Anyone else hear that a partial fill of E85 can be helpful when this happens? I know it has a very high octane equivalent but not sure how else it impacts the engine...