[carl_d]

Can someone tell me what my Euro 325 is tuned for by BMW from the factory? Is it tuned for 98 RON and anything lower will degrade performance and anything higher will give me nothing extra?

The fuel cap say I can used 95, 98, 100 or a higher RON ... this implies using anything higher than 98 will give me better performance. Is it possible the engine is already mapped for 100 RON and when using 98 its retards the ignition?

[epiphone3]

Originally Posted by carl_d

Can someone tell me what my Euro 325 is tuned for by BMW from the factory? Is it tuned for 98 RON and anything lower will degrade performance and anything higher will give me nothing extra?

The fuel cap say I can used 95, 98, 100 or a higher RON ... this implies using anything higher than 98 will give me better performance. Is it possible the engine is already mapped for 100 RON and when using 98 its retards the ignition?

my understanding is that if you use the higher octane, the Computer will advance the ignition appropriately (to a point) to take advantage of the better fuel.

I heard previously that BMWs are mapped for 98 RON and will advance ignition if you put in 100 RON. You will probably not notice the full effect until you have through run a couple tanks of 100 RON, however.

I think that super high octanes like various race fuels will be outside of the scope of what the computer can do... but I am not sure about this one.

In Canada, I use 91 AKA which is, I believe, equivalent to 95 RON. I believe that our cars here in North America must be adjusted differently or just run with slightly retarded timing all of the time. Europeans are lucky for having high quality fuel (although it is very expensive!)

[carl_d]

Thank you for the info. I've not seen 100 RON in the UK, I can get 99 RON (slightly more expensive and use all the time now from Shell or Tesco) and can also get 102 RON (3x the price from limited BP outlets).

Originally Posted by epiphone3

my understanding is that if you use the higher octane, the Computer will advance the ignition appropriately (to a point) to take advantage of the better fuel.

I heard previously that BMWs are mapped for 98 RON and will advance ignition if you put in 100 RON. You will probably not notice the full effect until you have through run a couple tanks of 100 RON, however.

I think that super high octanes like various race fuels will be outside of the scope of what the computer can do... but I am not sure about this one.

In Canada, I use 91 AKA which is, I believe, equivalent to 95 RON. I believe that our cars here in North America must be adjusted differently or just run with slightly retarded timing all of the time. Europeans are lucky for having high quality fuel (although it is very expensive!)

[epiphone3]

I would use the Shell V-Power 99 RON if I were you as 3X the price for 102RON is kind of a waste of money, in my opinion.

[danielt]

In Australia we have Shell V-power Racing which is 100 Octane with 5% ethanol. We also have V-power which is 98 Octane. Is the 5% ethanol going to be harmful to the 335i?

[epiphone3]

Originally Posted by danielt

In Australia we have Shell V-power Racing which is 100 Octane with 5% ethanol. We also have V-power which is 98 Octane. Is the 5% ethanol going to be harmful to the 335i?

The ethanol definately won't hurt the 335i, however, the ethanol may cost you a slight penalty in fuel mileage versus fuel of the same octane number but with no ethanol.

[Brunotheboxer]

who is RON?

[whippersnapper]

Originally Posted by Brunotheboxer

who is RON?

you don't know RON MON?

[Brunotheboxer]

Originally Posted by whippersnapper

you don't know RON MON?

RON Howard?

[epiphone3]

RESEARCH OCTANE NUMBER.

In the states, we use AKA which is determined as follows: (RON + MON)/2 = AKA

I can't remember what MON stands for

[jhbodle]

Hey carl_d,

The official BMW horsepower ratings are obtained using 98RON petrol for the 6 cylinder engines. The 4 cylinder engines horsepower ratings are obtained using 95RON fuel.

So basically if you want all 218 horses, use at least 98 octane fuel. Shell V-Power is my choice at the moment - I noticed the difference the moment I filled up with it after using Optimax.

[ADHD]

shit the most we got here in the states is 91octane.. i never seen RON before

[Brunotheboxer]

Originally Posted by ADHD

shit the most we got here in the states is 91octane.. i never seen RON before

In MA we have 93 octane at every station.:rocks:

[ADHD]

Originally Posted by Brunotheboxer

In MA we have 93 octane at every station.:rocks:

damb cali must be against 93..i think ive seen it at some 76 stations in la but not in the desert where i live!

[Jaws]

Originally Posted by epiphone3

RESEARCH OCTANE NUMBER.

In the states, we use AKA which is determined as follows: (RON + MON)/2 = AKA

I can't remember what MON stands for

I must be missing something. Is Calgary in the US?

[Gary]

Originally Posted by epiphone3

RESEARCH OCTANE NUMBER.

In the states, we use AKA which is determined as follows: (RON + MON)/2 = AKA

I can't remember what MON stands for

MON=motor octane number and is measured at load

[ska///235i]

Research Octane Number (RON)
Motor Octane Number (MON)

in the USA.....is Anti-Knock Index (AKI)

Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2

I'm confuse .... I'm guessing the PON (our gas station) is the average #s of the Ron & Mon

Lets all "Knock the shit outta our engines for some serious Knock resistance"

[Convertible]

More on Fuels.

http://www.e90post.com/forums/showthread.php?t=37781

[carl_d]

Thanks Jay. What if we put a higher RON in, do we get more power?

Originally Posted by jhbodle

Hey carl_d,

The official BMW horsepower ratings are obtained using 98RON petrol for the 6 cylinder engines. The 4 cylinder engines horsepower ratings are obtained using 95RON fuel.

So basically if you want all 218 horses, use at least 98 octane fuel. Shell V-Power is my choice at the moment - I noticed the difference the moment I filled up with it after using Optimax.

[jhbodle]

Originally Posted by carl_d

Thanks Jay. What if we put a higher RON in, do we get more power?

We sure do! Won't be much, but every little helps! I can't remember how I did it now, but I worked out that I was probably getting around 220-225bhp from my 325 using the 9RON fuel.