What grade gas you running in 3.0's

[JCL]

I just wonder, is it ok that I put Shell V-power (100 octane) in my 4.8 since I bought it? I think it's ok, because I asked in BMW service here in Geneva, they told that it is all right. Also he told me that its not good to go down with gasoline which has lower octane.

Originally Posted by DINANM3

Ive 100 octane in my M5 and M3 and it ran great. I was gonna put some in my X5 just for the hell of it this summer

DinanM3, you seem to be confusing RON with pump octane. The poster who asked the question is in Geneva. 100 RON in Geneva is very close in anti-knock properties to 93 pump octane in North America. Your 100 octane fuel in a road vehicle doesn't make a lot of sense, as the engine was not designed for it.

[Riyad Aliyev]

Originally Posted by JCL

DinanM3, you seem to be confusing RON with pump octane. The poster who asked the question is in Geneva. 100 RON in Geneva is very close in anti-knock properties to 93 pump octane in North America. Your 100 octane fuel in a road vehicle doesn't make a lot of sense, as the engine was not designed for it.

But i think in Geneva, V-power from shell is an 100 octane, and nothing else, because if v-power is equal to 93, (as i understood) then what is "Sans plomb 93" also which is offered in Shell gas stations?
Because if this is something that is even lower... A friend of mine has Mazda rx-8 and he puts Sans plomb 93 into his tank, and i think it wouldn't run on that if it would be something les than 93.

[JCL]

Originally Posted by Riyad Aliyev

But i think in Geneva, V-power from shell is an 100 octane, and nothing else, because if v-power is equal to 93, (as i understood) then what is "Sans plomb 93" also which is offered in Shell gas stations?
Because if this is something that is even lower... A friend of mine has Mazda rx-8 and he puts Sans plomb 93 into his tank, and i think it wouldn't run on that if it would be something les than 93.

You need to determine what the 100 V Power, and 93 sans plomb (unleaded) are in terms of RON. RON is the usual measurement in Europe. There is a 6-7 point spread between RON and pump octane, which is (R+M)/2, where R equals RON and M equals motor octane method. Again, it is not a precise conversion because it depends on the specific fuel.

I would guess that the 93 unleaded your friend uses is very close to 87 pump octane in North America. Just as with the BMW engine, a Mazda will run fine on 87 pump octane, it just may not develop all of the power it is capable of.

[DINANM3]

Originally Posted by JCL

DinanM3, you seem to be confusing RON with pump octane. The poster who asked the question is in Geneva. 100 RON in Geneva is very close in anti-knock properties to 93 pump octane in North America. Your 100 octane fuel in a road vehicle doesn't make a lot of sense, as the engine was not designed for it.

The M5 and M3 i put them in were modified not stock. The M3 was superharged. And beleive me it made a difference.
I was just saying that 100 ocatane in a stock 4.8 wont hurt it. Not sure if it will help it.

[JCL]

Originally Posted by DINANM3

The M5 and M3 i put them in were modified not stock. The M3 was superharged. And beleive me it made a difference.
I was just saying that 100 ocatane in a stock 4.8 wont hurt it. Not sure if it will help it.

DINANM3: Thanks for that. Yes, with those modifications I am sure you can use all the knock resistance you can find. My comment was that we should keep clear what the figure 100 means. Your 100 pump octane isn't the same as 100 RON.

Jeff