BMWs do not require Premium fuel...Only recommended?

[J0E]

Originally Posted by terrapen73

Do you all not have 93 octane? I have not driven much out west and haven't paid attention to the octane available. Everywhere I normally travel on the east coast has 93, 91 or 89, and 87 octanes available. Some stations will have 100+ race gas available as well. These are normal gas stations, nothing special. Just curious how different things may be right here in the US even.

High altitude stations don't even carry 93 octane. Out here in Colorado, 91 is the best you are going to get so that's what all my cars get. It doesn't hurt as much because 91 octane out here is about $1.50 cheaper than 87 in California

[Mr Marcus]

My 135i has a strict diet of 98RON petrol only. The owners manual says minimum standard 95RON it's fairly clear.

I have no idea why you US guys are talking about using 85 or 87 but I wouldn't put that shit in my engine.

[Turbolader]

It's because we measure fuel using the AKI. Octane, for us, is calculated MON + RON /2 for our octane calculation.

US 91 Octane = 95RON
US 93 Octane = 98RON (Depending who you ask)
US 94 Octane = 98 RON

I'm sure if you put 87 US octane in your 135, it will be fine. Not great, but it will work. Knock sensor will kick in, and I'm sure if you flog it enough, you could even get a CEL. I'm sure BMW designs for the worst in the country, which to my knowledge is 85 US octane, at higher elevations. Why? Because:

1. Somebody is going to consciously do it. Why? know knows.
2. More often, someone is unconsciously do it. Why? Habit, wrong pump color, or tanker truck put it in the wrong tank.

I do find it amusing though. Gasoline is around $4 a gallon right now. I pay a lot more than that. Premium is usually 20 cents more a gallon. So, you want to save 5%......on a car that costs how much? Sure if gas cost $1.00 a gallon, then maybe 20% would be enough to warrant the switch, but 5%? it's a deal at that price. I wish I could pay another 20 cents to get 4-6 more octane points! (And no, the octane boosters aren't really worth it because they define a point as 0.10 octane, not an actual 1.00 point)

[GeeRam]

I've only fed mine 99RON Shell V-Power since the end of the running in-period

[Mr Marcus]

Thanks for the explanation Turbolader, that makes sense now.

I had this hideous image of you guys pumping the car full of what would effectively be 2 stroke lawn mower petrol and I started breaking out in a sweat!!

[RPM90]

[QUOTE=Turbolader;11515544

I wish I could pay another 20 cents to get 4-6 more octane points! (And no, the octane boosters aren't really worth it because they define a point as 0.10 octane, not an actual 1.00 point)[/QUOTE]

Do you have a 100 octane tune?

We have a 100 rated gas at a local station.
I believe right now it's close to $5.50 per gallon.
It's odd pricing on that "race" fuel because the price per gallon doesn't seem to go up by an equal amount to the price of the regular fuels, meaning it's cost get's lower as regular prices go up.
Strange. Or, I saw that price before they increase it.
I'll have to check it now the gas prices have really risen by a good amount. Could be they don't sell much of it and supply is good compared to demand.

[RPM90]

Originally Posted by Mr Marcus

Thanks for the explanation Turbolader, that makes sense now.

I had this hideous image of you guys pumping the car full of what would effectively be 2 stroke lawn mower petrol and I started breaking out in a sweat!!

I use 87 for the John Deere lawn tractor. It's a V-twin 4 stroke. Very smooth compared to the single cylinder models, and it's quiet too.

[cvandenhaute]

One little detail that many of you seem not to take into account : the maintenance interval of these cars. Putting 87 octanes in a car that has to get an oil change every 3000 or 5000 miles if fine for me, not in a car that is supposed to get a maintenance only 15,000 miles. Fuel quality in Europe is one of the reasons that the maintenance intervals are now as large as 30,000km but I would never risk doing that with 87 or 89.
I had a 2007 Miata back in Europe. 98 was recommended, not required but I can tell you that there was a significant difference in the way that the engine ran on 98. On 95 the engine was coarse and unresponsive, put 98 in the tank and it was a different car... I can't help thinking it makes a difference in the long run.
For my 128i, I never even remotely thought putting anything else than Shell V-Power or top equivalent at BP or Mobil...

[Tom K.]

Originally Posted by cvandenhaute

Fuel quality in Europe is one of the reasons that the maintenance intervals are now as large as 30,000km but I would never risk doing that with 87 or 89.

While US fuel quality apparently is not up to that found in Europe, I'm not understanding how you equate octane with fuel quality. And is there any hard evidence that running higher octane = longer change intervals?

Tom

[fraz]

To each their own. The users manual for my 2012 128i vert does indeed state to use a minimum octane of 87.

As mentioned on another thread, six new Bimmers, three 3's, two 5's, and a Z3 Roadster. The Z3 was sold after a trouble-free 106K miles, and 13 1/2 years. I never ran more than 87 octane in any of them......and never noticed reduced performance. I guess I need to "track" my car and check it out......not.

[RPM90]

Originally Posted by fraz

To each their own. The users manual for my 2012 128i vert does indeed state to use a minimum octane of 87.

As mentioned on another thread, six new Bimmers, three 3's, two 5's, and a Z3 Roadster. The Z3 was sold after a trouble-free 106K miles, and 13 1/2 years. I never ran more than 87 octane in any of them......and never noticed reduced performance. I guess I need to "track" my car and check it out......not.

Using a lower octane fuel in a non turbo NA engine is not as risky as in a turbo engine, especially a turbo with high compression like the N54 and N55 and the new N20.

Higher octane doesn't make more power. If the engine is designed to attain max performance on 87/US octane, then using a higher octane has no added benefit.
Octane is simply a data point regarding the fuels ability to resist detonation. That's why high octane fuels are "recommended" in turbo applications. When you increase compression ratio and/or add turbo boost, there is much greater chance of detonation occurring.

You can use lower octane in engines with a 'knock sensor'. When knock occurs the ECU will sense it via the sensor and will do what it needs to do to stop the knock event. The ECU will retard timing. Retarding timing results in the engine not running at it's best, and will not produce the power you paid for. Advancing timing allows for maximum power production, and the engine is then running at it's best as it was designed to do.

Knock events can still occur in an engine even if high octane is being used. Under heavy load conditions and/or high ambient conditions knock can still occur. The sensor will sense it and pull timing to stop it. Once under control the ECU will continue to advance timing until knock occurs again. The ECU is constantly monitoring things and adjusting.

In the winter months when ambient temps are low one could run lower octane gas as chances for knock are much lower. You can still achieve maximum power with lower octane as long as knock doesn't occur or last.
The ECU will continue to advance timing and keep it advanced as long as knock isn't occurring. This explains why some people are running lower octane in their turbo's and NA N52's, and don't notice any difference.
Still, in the final analysis, you paid a good amount of money for a certain level of performance. I don't see a good reason to run lower than recommended octane fuel. The proper octane fuel ensures your engine will run at it's best. The major reason I like BMW's is because of the performance they build into their automobiles. No need to lower the performance just to save a few bucks.

End rant:

[Somebuddy]

The three or four bucks extra it costs to fill up with high octane is quickly recovered in a bit better fuel mileage............thats enough justification for me.

[Ryan9095]

Physically as long as you use the same fuel EVERY TIME you will not have a problem. Don't put 93 in one week and 87 the next. As long as you stay consistent you're golden.

[doublevanosrc]

I love filling up my car with premium 93 every time, makes me feel like I'm buying her the equivalent of a steak dinner in the fuel world haha.

[RPM90]

Originally Posted by Ryan9095

Physically as long as you use the same fuel EVERY TIME you will not have a problem. Don't put 93 in one week and 87 the next. As long as you stay consistent you're golden.

Not sure what you're getting at here.
Alternating fuel grades is nothing different than using lower than recommended octane.
Alternating fuel grades affects detonation no more nor less than using low octane. IOW, alternating fuel grades is a non issue.

Consistently using the recommended octane grade will give best performance.

[Bimmer-Bob]

Originally Posted by fraz

The users manual for my 2012 128i vert does indeed state to use a minimum octane of 87.

And a recommended octane of 91.

[imstupidsorry101]

Soooooo is plus a no no lol =x