idoke1

iTrader: (5)

While refueling, i forgot to use 91 octane. When i finally noticed, it was 10.8 gallons full from empty. I was PISSED...... I immediately stop the pump. I drove it home slowly and need advice. Will i be fine with 87 gas in it for now or should i empty it for 91?

lobuxracer

iTrader: (2)

Just drive it. Don't beat on it, the engine won't like it, and your mileage will probably suck pretty bad, but it should not be a major problem.

ISF4life

iTrader: (30)

If u want just get a tube and suck it out as much as you can that would make you feel a bit better

Vervish

iTrader: (4)

Add some octane booster it might help. I added regular in pretty heavily modded Subaru legacy one time. I was logging a ton of knock and timing was being pulled on normal off boost driving. Once I added the octane booster, the knock sensor went quiet and the ecu started to slowly add timing again..even under boost. I think octane boost is more than snake oil in these situations.

EpikOEM

Don't worry OP. I have done this myself with my old car. After the new engine, it was fine....j/k

No worries, I have done this and it was fine. I did notice my gas mileage sucked, but after that tank of gas, I refilled it with 93 octane and all was fine again.

chris07is

iTrader: (10)

your car will lose about 100hp, its now 316hp. still faster then IS 350...lol..just kidding bro, it should be fine...

idoke1

iTrader: (5)

^^lol. Thanks you guys. I'll ride it out and drove it slow. Lesson learned

ihiryu

iTrader: (7)

Just drive it normal. Cars have knock sensors, if it sees knock, or lean AFR's, it'll retard the timing. It'll just be slower than usual.

I've even done this on accident with my mazdaspeed miata (stock turbo) and people online freak about it, it's not that big of a deal, just drive it normal....

Meraki Autoworks

iTrader: (8)

Octane booster should help it.

vbb

iTrader: (3)

I've done the opposite and put premium (93 octane here) in my Nissan Titan by accident because I had just filled up my ISF the day before and wasn't even thinking. Now THAT was a total waste of money.

But as has been said in virtually every other response, you'll be fine. I've known people who have purchased luxury cars that only take premium, but almost always put regular or mid in the tank because they were cheap and didn't care about performance and only cared that they had a luxury car. As stupid as that was, they didn't destroy their cars (though I feel bad for whoever might have bought the car next).

RichFlair

iTrader: (2)

Just pulling your chain

Mjade

Hahahaha too bad there's anti siphon on the iSF.


Dump some octane booster in it and just burn it off. Don't drive it hard. Just be a little extra nice to her until you burn it all off.

lobuxracer

iTrader: (2)

Octane boosters are complete BS. They do not work when the gap is 3 points. Maybe 0.3 points, but no way will any commercial octane booster make 87 perform like 91.

You have the right idea. Just drive easy, realize you're going to get really crappy mileage, and put the good stuff in it next time.

Did I ever mention one of the reasons I left California was the BS 91 octane that behaves like 89 octane? Gotta love 93 at all the pumps in metro ATL usually for less than 87 in Cali! I send my buddy in Sacramento pictures of our stupid low prices every time I think about him moving here.

I8ABMR

This is no issue. Will not hurt the car. The ECU will tweak things and you will lose HP and mpgs. Guys on the LS460 forum used to discuss this all the time

Twotwo

So many people are mislead this was not going Harm your car