[BashShah]

Wife took car out last night.
Gas light came on....
She went to esso in Canada and put 30 liters of 87 octane.

What should I do other than try to empty it ASAP by driving it in DS all the time.
Any additive recommendations to bring the octane level up.

Thanks in advance.
DN

[RoamPT]

I don't think it has to do with the gas, they do recommend 91, but putting 87 once it won't do any harm. See which error is it, connect to the obd port.

[Gizm0]

You'll be fine, fill up the rest of the tank with 93, and take it easy on the gas until the tank is empty. It won't hurt the engine, just hurt performance and gas mileage...

[DF]

Just burn it off. It wont hurt the car.

[BashShah]

Thanks guys.
I wanted to side with caution on really a sensitive car.

Thanks guys.
DN

[jadnashuanh]

The knock sensors will compensate for most of it. If you take it easy - no heavy acceleration, hauling up a grade, high-speed cruise, the vehicle doesn't need higher octane. But, it can only compensate so far. As soon as you do get some room, as others have said, put the highest octane in it you can find, then return to your normal operation. Octane enhancers need to be checked before using, if you go that route, for compatibility. Those that contain mostly alcohol may make things worse - check your owner's manual. It's not catastrophic as long as you don't go out on the highway and cruise up a mountain pass at high speeds and loads...it would have been okay at 89.

How your country measures octane can affect the end result, too. There are two accepted methods, some use one, others the second, and still others use the average of those two methods, so it isn't as clear as it might be.

30-liters would only have been about 1/2-tank...just fill it with the best stuff you can find and don't worry.

[Infamy]

Just throw a can of octane booster in. Should help out a bit.

[Frenk]

Originally Posted by RoamPT

I don't think it has to do with the gas, they do recommend 91, but putting 87 once it won't do any harm. See which error is it, connect to the obd port.

not true. Minimum is 89. 87 may have hurt engine

[rowingone]

87 hurt engine . . such bs!

[roundle]

Not going to be a problem. You'll probably see a 5% drop in MPG.

If you didn't have a modern engine with a knock senor, you'd probably hear some pinging and potentially destroy a plug or two.

[cdgatti]

people you are over reacting. bmw recommends the octane they do for 2 reasons, they aren't paying for the gas and the car (all cars do) will run better (allows more advanced timing) with the higher octane fuel especially in hot weather. Don't worry you can run 87 all the time and not damage the car.

[bvanlieu]

Put a gallon of toluene in there. You can do the octane math with some searching. The little octane boost bottles are marketing. Toluene and xylene are real

Yes the ECM can compensate but for 12-15 you can raise it a bit for safety then fill with 93 when you burn off half a tank.

- b

[Kolyan2k]

Originally Posted by Frenk

not true. Minimum is 89. 87 may have hurt engine

I was under the impression minimum for 335 is 91AKI, and no 87 will not hurt anything

[Kolyan2k]

Originally Posted by cdgatti

people you are over reacting. bmw recommends the octane they do for 2 reasons, they aren't paying for the gas and the car (all cars do) will run better (allows more advanced timing) with the higher octane fuel especially in hot weather. Don't worry you can run 87 all the time and not damage the car.

Where did u get that? Engines are designed to run on specific octane or higher. Most engines that are designed to run on 87 will not run better on 89 or 93, and will not see any performance or fuel economy boost

[cdgatti]

Where do you get that? Ever since engines have come with knock sensors to detect pre-detonation before you will ever hear it and aultomatically retard the ignition timing to prevent it from becoming detrimental, there will be no damage running 87 octant in a car that says it runs best with 91. Read the manual it will say the same.

[Kolyan2k]

Originally Posted by cdgatti

Where do you get that?

Everywhere if you Google

[Kolyan2k]

Originally Posted by cdgatti

Where do you get that? Ever since engines have come with knock sensors to detect pre-detonation before you will ever hear it and aultomatically retard the ignition timing to prevent it from becoming detrimental, there will be no damage running 87 octant in a car that says it runs best with 91. Read the manual it will say the same.

? I wasn't talking about that. You said going higher then recommended octane will make engine run better. That's not true in most cases and unless noted in manual.

[cdgatti]

Yes is not true for all cars and it varies with each model. Years ago C&D did a test with an M3 and showed that it made more power as you stepped up the AKI to 96, then no more benefit. Also climatic conditions and turbo boost and intercooler efficiency play a big role in determining the temperature of the air/fuel mixture before combustion. BMW has reduced the AKI to 89 for the turbo f30 cars but it's HP/torque numbers are based on 91. They also recommend BP fuels! Not even a top tier gasonline.

[cdgatti]

Originally Posted by Kolyan2k

Everywhere if you Google

the internet is full of uninformed wannabe auto engineers

[RoamPT]

Originally Posted by Frenk

not true. Minimum is 89. 87 may have hurt engine

It doesn't hurt your engine, doesn't matter if it's 89 or 87. It's just affects the car performance and gas mileage, that's all. 87 octane is equivalent to the 95 octane in europe, and i used to fill it my cars with 95 and everybody else too. Don't worry just burn that and put premium.

[Kolyan2k]

Originally Posted by RoamPT

It doesn't hurt your engine, doesn't matter if it's 89 or 87. It's just affects the car performance and gas mileage, that's all. 87 octane is equivalent to the 95 octane in europe, and i used to fill it my cars with 95 and everybody else too. Don't worry just burn that and put premium.

87aki=91ron < minimum for most japanese and american cars (none-performance)
95ron=91aki < minimum for most euro and performance cars

[fredcase]

Is your car a 335?

Higher Octane has a higher resistance to detonation from compression.

Let the car idle for as long as possible to burn as much gas as possible. Half tank would be good.Then top up with husky 94 or petro Canada 94. And stay out of boost. Additives and octanes boosters do absolutely nothing.

I'm no car guru but used to be a automotive machinist and thought this should have been an easy one. So much false information in this thread.