Would using 89 octane be bad for the engine?

[e90bimmer]

Such as decreasing intervals needed for oil change

Not talking about economy or performance, as that has been discussed to death

Oh, and I'm talking about the N52 engine.

[NFerber]

Yes, there are reasons that BMW requires 91+ octane. You can use 89 for short periods of time and the engine will adjust, but in the long term it will be detrimental to your car.

[e90bimmer]

But my manual says 91+ is not required, just recommended.

[nmonfared]

The money you'd save in gas costs would be offset by engine maintenance later on. Do yourself, and your engine, a solid and just go with the 91+. You bought a BMW, not a Honda.

(No offense to anyone with Hondas out there :shifty )

[Sstroudwku]

The reason for the 91+ is engine timing. By using a higher octane they can advance the timing creating more power. Using lower octane "which essential burns faster" you cause a predet in the combustion chamber. Often you hear this referred to as "pinging" you'll hear it under most during WOT. I'd honestly suggest using Shell Vpower 93 or Sunoco Super 94. These engines were developed in Germany using German fuels, which as most Americans dont know have a MUCH higher quality standard. Our 93 is more like there 87, in America we allow a certain amount of water in our fuel, a lot more than Europe allows.

[floydr]

The reason for the 91+ is engine timing. By using a higher octane they can advance the timing creating more power. Using lower octane "which essential burns faster" you cause a predet in the combustion chamber. Often you hear this referred to as "pinging" you'll hear it under most during WOT. I'd honestly suggest using Shell Vpower 93 or Sunoco Super 94. These engines were developed in Germany using German fuels, which as most Americans dont know have a MUCH higher quality standard. Our 93 is more like there 87, in America we allow a certain amount of water in our fuel, a lot more than Europe allows.

Sorry, but I have to speak up - there is much MISS-information here.
1) The EU uses different measurements for Octane than the US. Their 91 is equivalent to our 87, 95 to our 89 and 98 to our 91/92. The only real differences between EU and US fuels are much higher sulfur in the US, and up to 10% ethanol (which many point to as the cause of HPFP failures). The US does not allow water in fuel.
2) BMW engines have, for over 10 years, had knock sensors that detect pre-detonation and cause the computer/ECU to retard the timing. Our engines can run perfectly well on 87 or 89 "octane" fuel. However, you pay the penalty in reduced power and fuel mileage. Pre-detonation is less of a problem on the turbo engines with their direct injection, however the N52 engine may see a more significant loss of power/efficiency.

People that have looked at the matter (using 87/89 octane fuel) have pretty much said that you will lose enough in poorer mileage to offset (mostly) the lower cost of regular. Mid-grade is more of a toss-up.

Google "Running On Regular: Do Premium Vehicles Really Need Premium Gasoline? From Stan Baldwin online" and you will discover quotes direct from BMW representatives that you can run regular/mid.

[Sstroudwku]

Sorry, but I have to speak up - there is much MISS-information here.
1) The EU uses different measurements for Octane than the US. Their 91 is equivalent to our 87, 95 to our 89 and 98 to our 91/92. The only real differences between EU and US fuels are much higher sulfur in the US, and up to 10% ethanol (which many point to as the cause of HPFP failures). The US does not allow water in fuel.
2) BMW engines have, for over 10 years, had knock sensors that detect pre-detonation and cause the computer/ECU to retard the timing. Our engines can run perfectly well on 87 or 89 "octane" fuel. However, you pay the penalty in reduced power and fuel mileage. Pre-detonation is less of a problem on the turbo engines with their direct injection, however the N52 engine may see a more significant loss of power/efficiency.

People that have looked at the matter (using 87/89 octane fuel) have pretty much said that you will lose enough in poorer mileage to offset (mostly) the lower cost of regular. Mid-grade is more of a toss-up.

Google "Running On Regular: Do Premium Vehicles Really Need Premium Gasoline? From Stan Baldwin online" and you will discover quotes direct from BMW representatives that you can run regular/mid.

I'm afraid you're misinformed on the water content. Each state has a designation as to the % of acceptable water content in fuel. Each state is different, after living in Oregon is when I learned this. It's one of the few states that allow a much higher level than others.

Knock sensors fail.. and even with the advanced engine electronics predet can still happen. It has to happen over X period of time for a knock sensor to retard timing. I've rebuilt a pre-vortec 350 that had spun the front main bearing and snapped a rod. Engine had knock sensors and still would rev past 4k rpm... So they aren't completely reliable.

I know the EU rates octane levels differently... but their fuels are a higher quality than ours.

[floydr]

Knock sensors fail.. and even with the advanced engine electronics predet can still happen. It has to happen over X period of time for a knock sensor to retard timing. I've rebuilt a pre-vortec 350 that had spun the front main bearing and snapped a rod. Engine had knock sensors and still would rev past 4k rpm... So they aren't completely reliable.

If a knock sensor fails, it will throw codes and set the CEL. At least on BMWs.

[Sstroudwku]

If a knock sensor fails, it will throw codes and set the CEL. At least on BMWs.

Yes it will if it completely fails, but it wont retard the timing on a single predet or knock. It's an algorithm of occurrences.

[floydr]

I'm afraid you're misinformed on the water content. Each state has a designation as to the % of acceptable water content in fuel. Each state is different, after living in Oregon is when I learned this. It's one of the few states that allow a much higher level than others.


This is a consumer-affairs thing related to CONTAMINATION, not "acceptable" with respect to the EPA's regulations. You're talking about water picked up by transport (especially by ethanol in the gas) or condensation. Entirely different thing.

[Sstroudwku]

This is a consumer-affairs thing related to CONTAMINATION, not "acceptable" with respect to the EPA's regulations. You're talking about water picked up by transport (especially by ethanol in the gas) or condensation. Entirely different thing.

Ok in technical terms it's a level of acceptable contamination which is quite a bit more acceptable here than it is in the EU. It's accepted to say our US petrol SUCKS ASS. Do you work for an OIL company? lol

[floydr]

Ok in technical terms it's a level of acceptable contamination which is quite a bit more acceptable here than it is in the EU. It's accepted to say our US petrol SUCKS ASS. Do you work for an OIL company? lol

Petrol? What's that?:stickoutt

BTW, I don't put petrol (or gasoline) in my tank - I've got an oil-burning 335d.

The oil industry sucks - they'll do anything and everything to make a profit. Including cutting all the corners they can. And our government is too wussy to make them do the right thing.

But don't let that blind you to the fact that a US-spec BMW runs fine over there, and a German/UK/France-spec BMW runs fine over here (ignoring ethanol and HPFP issues). The EU/US(CA) gasoline specs are (not surprisingly) quite similar. And don't forget that the US was the first market to eliminate lead, 1st to require many of the formulations used around the world.

[Sstroudwku]

Petrol? What's that?:stickoutt

BTW, I don't put petrol (or gasoline) in my tank - I've got an oil-burning 335d.

The oil industry sucks - they'll do anything and everything to make a profit. Including cutting all the corners they can. And our government is too wussy to make them do the right thing.

But don't let that blind you to the fact that a US-spec BMW runs fine over there, and a German/UK/France-spec BMW runs fine over here (ignoring ethanol and HPFP issues). The EU/US(CA) gasoline specs are (not surprisingly) quite similar. And don't forget that the US was the first market to eliminate lead, 1st to require many of the formulations used around the world.

Lol Petrol is the proper name along with calling our petrol here complete rubbish. :D

[mryakan]

Knocking may occur with 89, esp. with extreme temperatures and high revs. Knocking is bad and knock sensors can fail. If the fail and you redline, guess what the result is... Booom! Not worth it. Sure BMW says you can run on 89, but I would recommend that you only do that if you cannot get 91+ and in that case avoid higher rev band. In any case, the economy of it will probably not work out in your favor due to the lower energy output and timing retardation.

[Sstroudwku]

Knocking may occur with 89, esp. with extreme temperatures and high revs. Knocking is bad and knock sensors can fail. If the fail and you redline, guess what the result is... Booom! Not worth it. Sure BMW says you can run on 89, but I would recommend that you only do that if you cannot get 91+ and in that case avoid higher rev band. In any case, the economy of it will probably not work out in your favor due to the lower energy output and timing retardation.

If you work the math. My 15.9gallon tank if completely empty would hold 61.85 in 89 octane @ 3.89/gal "current price". The same tank holds 63.76 of Shell V-Power 93 octane @ 4.01/gal "current price". so you save less than $2/tank. Say you put 3 tanks a month in over a year you've only saved $72... equiv to a little more than an extra tank. Possible cost in damage..... well lets just say it's got more zeros at the end.

[pappy1911]

With all this discussion, my method is to alternate between 89 and 93 octane on perhaps a half tank. This should mix out to 91 octane.....
In other words, when the tank is about half empty, I'll fill with 93..next half tank, then the 89.
I rarely go above 4500 rpm....

[19Dbmw]

I understand the math.lol

IMO if you buy a sports car then give her what she was designed for! If you are worried about 2 bucks a tank then maybe you should look to a different bread of vehicle!! I'm just saying!!

[Sstroudwku]

I understand the math.lol

IMO if you buy a sports car then give her what she was designed for! If you are worried about 2 bucks a tank then maybe you should look to a different bread of vehicle!! I'm just saying!!

All I can say is, if two bucks makes or breaks you... You shoulda bought a civic or Corrola

[pappy1911]

All I can say is, if two bucks makes or breaks you... You shoulda bought a civic or Corrola

It's not about penny pinching my money, it's the principal of feeding the money grubbing oil barons any more than I have to..

A few dollars or $10/gal, I can afford it. It pains me to help support them...

[Philz BMW]

I understand the math.lol

IMO if you buy a sports car then give her what she was designed for! If you are worried about 2 bucks a tank then maybe you should look to a different bread of vehicle!! I'm just saying!!


All I can say is, if two bucks makes or breaks you... You shoulda bought a civic or Corrola

COOL!

Every time you guys fill up, paypal me $2 each. It's only $2, sh*t why should you care!!

No seriously. If I could get everyone on these forums that doesn't give a rip about a mere $2 to paypal me each time they filled up, I'd be set.

[pappy1911]

IMO if you buy a sports car then give her what she was designed for!

I am...91 octane is what my manual calls for..

[mryakan]

It amazes me how some people have no problem paying for unnecessary extra oil changes, yet refuse to pay for better gas!
I mean why not buy Walmart wine while at it, gets you as drunk as the expensive stuff! And if you say you pay for quality, I say your car deserves it too.
In the end it is your monies. Just remind me not to buy your second hand cars.

[Sstroudwku]

It's not about penny pinching my money, it's the principal of feeding the money grubbing oil barons any more than I have to..

A few dollars or $10/gal, I can afford it. It pains me to help support them...

If you really feel that way you could get a diesel and swap out the fuel lines for the use of biodiesel. Then you just have to filter and refine your own biofuel and never pay a baron again. "not sarcastic I'm serious" I know people here local that do this on their olllld toyo diesel trucks that are just regional commuters. "Never more than 50miles from home".

[BillD1953]

Wow !!

[Sstroudwku]

Wow !!


What? Didnt expect to meet the passionate people here :) we love our cars.

[sleeeper]

The car runs best on Shell 93--If I wanted it to drive like a Civic, I would have bought one.

[ou8durian]

Knocking may occur with 89, esp. with extreme temperatures and high revs. Knocking is bad and knock sensors can fail. If the fail and you redline, guess what the result is... Booom! Not worth it. Sure BMW says you can run on 89, but I would recommend that you only do that if you cannot get 91+ and in that case avoid higher rev band. In any case, the economy of it will probably not work out in your favor due to the lower energy output and timing retardation.

Try 76 gas stations some sell 100 Octane here in California. I have not tried it yet. But in theory we should have no knocking, pinging...

[Ferruccio]

Knocking may occur with 89, esp. with extreme temperatures and high revs. Knocking is bad and knock sensors can fail. If the fail and you redline, guess what the result is... Booom! Not worth it. Sure BMW says you can run on 89, but I would recommend that you only do that if you cannot get 91+ and in that case avoid higher rev band. In any case, the economy of it will probably not work out in your favor due to the lower energy output and timing retardation.

Doesn't a piggyback JB3 basically rely on the engine's knock sensors to compensate for the funky new information being fed to the ECU? So, if a knock sensor fails with JB3 settings...?

[Fortybelow]

I have 3 reasons why I use 91 octane:

1. Manual calls for it.

2. Not sure if it holds true with my BMW, but with my commuter vehicle (Nissan Frontier) The extra mileage gained by running premium offsets the extra cost for the most part.

3. Not sure how it is in the US, but up here most regular/Mid-Grade fuels contain ethanol. Here is what BMW says about it:

“In combustion, ethanol provides less energy than gasoline, resulting in reduced fuel economy. When ethanol burns inside the engine, it tends to form a weaker mixture that may cause misfire, rough idle and cold start issues in your vehicle. In addition, engine components may deteriorate over time when in contact with ethanol”.

The Shell stations up here state on the pumps that Bronze contains up to 10% ethanol, Silver up to 5%, and V-Power contains no Ethanol so I run the V-power in both my vehicles.

[mryakan]

I have 3 reasons why I use 91 octane:

1. Manual calls for it.

2. Not sure if it holds true with my BMW, but with my commuter vehicle (Nissan Frontier) The extra mileage gained by running premium offsets the extra cost for the most part.

3. Not sure how it is in the US, but up here most regular/Mid-Grade fuels contain ethanol. Here is what BMW says about it:

“In combustion, ethanol provides less energy than gasoline, resulting in reduced fuel economy. When ethanol burns inside the engine, it tends to form a weaker mixture that may cause misfire, rough idle and cold start issues in your vehicle. In addition, engine components may deteriorate over time when in contact with ethanol”.

The Shell stations up here state on the pumps that Bronze contains up to 10% ethanol, Silver up to 5%, and V-Power contains no Ethanol so I run the V-power in both my vehicles.

+1. Been using Shell V-power on my BMWs (or 91oct before it was branded) since I moved to Canada in 1998. Never a problem in 13+ years, and I redline the car often.

[19Dbmw]

+2 I use Shell V -power in my vehicle as well. Really started noticing a difference when I switched over on the motorcycle and have been a fan ever since!!

[pappy1911]

.... and I redline the car often.

Be careful not to buy any of his used cars.....:eek:

[mryakan]

Be careful not to buy any of his used cars.....:eek:
A BMW engine was built to be redlined. Not every time mind you, but doing it often is not going to do any harm, esp. with the rev limiter kicking in very aggressively if you rev too high. In fact many claim that BMWs that are driven at high RPMs drive much better than ones that are driven at tame low RPMs. After owning my previous e36 for 10 years and 130K without a single powertrain issue whatsoever, I believe I can attest to the fact that redlining a BMW often is not a bad thing. Just follow the breakin procedure and do not go over 4.5K (or full throttle) until the engine oil is up too operating temps.

[sleeeper]

I have heard this before that BMW engines not revved are coming in with more problems...Happy Ultimate Driving!:buttrock

[pappy1911]

I have heard this before that BMW engines not revved are coming in with more problems...Happy Ultimate Driving!:buttrock

Care to elaborate??? What problems????

[sleeeper]

Care to elaborate??? What problems????

Well first, carbon builds up in every nook and cranny. Then a service light comes on that directs you to the dealer so that you can pay a fee for driving like a grandma, followed by a SA who 'test drives' your car to blow that crap out and reset the car's electronically-tuned self esteem! :D

[kaki11]

A BMW engine was built to be redlined. Not every time mind you, but doing it often is not going to do any harm, esp. with the rev limiter kicking in very aggressively if you rev too high. In fact many claim that BMWs that are driven at high RPMs drive much better than ones that are driven at tame low RPMs. After owning my previous e36 for 10 years and 130K without a single powertrain issue whatsoever, I believe I can attest to the fact that redlining a BMW often is not a bad thing. Just follow the breakin procedure and do not go over 4.5K (or full throttle) until the engine oil is up too operating temps.

+1 BMW' s are higher rpm cars as apposed to the lower rpm American cars such as the Mustang.

[Daneborough]

I only use Shell V-Power 98 RON in my 335i - current cost depending on the day of the week up to AU$1.60/litre - on today's exchange rate around US$6.00+/gallon - you do the math on how much to fill the tank! - if I was worried about this cost I would have bought a clunker that will run on much cheaper E10!

[Fortybelow]

I only use Shell V-Power 98 RON in my 335i - current cost depending on the day of the week up to AU$1.60/litre - on today's exchange rate around US$6.00+/gallon - you do the math on how much to fill the tank! - if I was worried about this cost I would have bought a clunker that will run on much cheaper E10!

Damn, Super Premium huh?

Would be nice but the only time I laid my eyes upon it in Canada was in Vancouver last summer. The octane rating was 94 (on the AKI index, which is equal to 98 RON) But if I remember correctly it was a Mohawk station which my mechanic basically told me to stay away from if possible. I know Chevron sells a 94 octane as well up here, but I really don't know much about it, nor is there one within 500 square kilometers from me lol.

Not too cheap in Canada either. Right now i'm paying CA$1.42 for a litre, which would work out to a little more than US$5.50 per gallon. You hit the nail on the head though, If I wanted something cheap and economical I would have bought a Yaris or something hilarious like that.