Iceman

R U kidding ?

93 octane ?

wow... what about 98 ???

I am surprised we have such a big variety on gasoline and you don't.

Rudy

I'm no expert but I think there's more than one way to measure "octane".

It's kind of like horsepower -- there's a US HP scale and a Euro HP scale.

Then again, if I'm wrong I won't be surprised...

kscarrol

I think Rudy is right, that we actually have slightly different scales, so that the difference between our 93 octane and your 100 is not as great as it may seem. Excuse my ignorance, but what is the term used in Germany/Europe, as I recall its not Octane like we use here in the US? I remember seeing the 545 manual I downloaded from BMW AG used the AKI or something like that. I wonder if 100 AKI = 100 Octane?

Dantheman

Here it is,

100 octane is not just 100 octane, because Europe and the US (Canada) uses different standards. Don't know about the rest of the world... In Europe, the Research Octane Number (RON) standard is used, whereas the US uses an average of MON and RON, the Anti-Knock Index (AKI). In comparison, AKI 94 octane in the US is the equivalent of RON 100 octane in Europe. Gasoline pumps typically post octane numbers as an average of two different values. Often you may see the octane rating quoted as (R+M)/2. One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94. It would be too simple to use an international standard I guess LOL

High octane gasoline does not outperform regular octane gasoline in preventing engine deposits from forming, in removing them, or in cleaning the engine. Nor does it improve performances. You should select the lowest octane grade at which the car's engine runs without knocking i.e 91 for E60. Occasional light knocking or pinging won't harm the engine, and doesn't indicate a need for higher octane. On the other hand, a heavy or persistent knock may result in engine damage.

Rudy

Okay then, what Dantheman said!!

Is this place great or what?

jtxc

SPECIALIST........WTFIT.........new to me, Rudy you got me here.....good Job

cidair

Select lowest octane, which not gives knocking? No performance increase with higher octane?

Am I missing something here? BMW M recommends highest ( 98 ) octane available for M cars.

So my 545 V8 will give the same performance and emissions with 91 as with 98??

Iceman

As I posted earlier, Shell advertises the 100 octane as beeing better for the engine, giving the engine an increase of power, less emmissions and higher mpg.

Some ppl believe in it, some don't.

I don't believe it, but I don't know it, because I'm no expert. So why play around ? BMW recommends 98 octane over here in Germany for V8 engines. I could use the regular, but why should I ?

The differences are measurable - you don't really "notice" a difference...

But a lot of ppl told me that the engines run smoother, what you should be able to feel while cruising... But I never used anything else since I have my "baby" and I never will !

I can't do anything wrong by using the Shell V-Power.


In Germany we go by the ROZ, "octane".

Link to explanation of ROZ MOZ SOZ (in German)

ULtraPLanet

I test drove a 530i and 645i on the autobahn and I would agree that around 210-220 kph the 530 starts to feel a little light up front. The 645 was a rock all the way up to 255 kph. It felt exactly the same at 100 kph as it did at 255 kph. Don?t know if it?s the aerodynamics or the extra weight up front from the v-8 but the 645 was much more stable than the 530i at speed.

Iceman

When going more than 250 Km/h the 545 feels a little lighter on the front, but still solid.
Up to 230 km/h it is rock solid!