[canuck2]

Sorry but actually from what I recall, according to my owner's manual, it specifically states 91 octane rating according to the (R+M)/2 method, which is how the gas grades are generally calculated in the US. From what I've seen this is how most car manufactures refer to octane ratings and would also believe is how they judge the type of gas they are using in their engine development/testing.....

[canuck2]

Originally Posted by sdorn

I guess that some would argue that it is cheap insurance to just go ahead and buy the highest octane fuel available. I figured it out, and over the three year lease on my car it would cost me around $500 more to use premium vs. regular and about $250 to use premium vs. mid-grade. To some that is cheap insurance. I will probably stick with the premium.

You may also notice a decrease in fuel economy running on lower grade gas which would further erode the cost savings.....not to mention performance decreases.....

[sdorn]

Originally Posted by canuck

Sorry but actually from what I recall, according to my owner's manual, it specifically states 91 octane rating according to the (R+M)/2 method, which is how the gas grades are generally calculated in the US. From what I've seen this is how most car manufactures refer to octane ratings and would also believe is how they judge the type of gas they are using in their engine development/testing.....

E90Fleet above posted that the fuel requirement is 91 RON. Also, the articles you posted state that Europe uses the RON rating rather than the PON rating that we use here in the U.S.

[canuck2]

Originally Posted by sdorn

E90Fleet above posted that the fuel requirement is 91 RON. Also, the articles you posted state that Europe uses the RON rating rather than the PON rating that we use here in the U.S.

OK - here is a clip from information on BMW's corporate site :

-----------------------------
The technical data specified applies to vehicles in the German market.

Max. output: the petrol engines of the BMW 3 Series Sedan are designed for RON 98 fuel. The engines may be run on RON 95 and RON 91 fuel with a decrease in power and an increase in fuel consumption.
-----------------------------

For the German market they indicate RON 98. For the US market they indicate octane 91 according to (R+M)/2 because that is generally how it is calculated here. I just checked my owner's manual and it definitely says (R+M)/2. Also the next time you fill up at the gas station look at the octane sticker and you will likely see (R+M)/2 underneath indicating that is how it was caculated. Not sure about any other countries.....forgot to add PON is the AVG of RON and MON or (R+M)/2.....

[sdorn]

Originally Posted by canuck

OK - here is a clip from information on BMW's corporate site :

-----------------------------
The technical data specified applies to vehicles in the German market.

Max. output: the petrol engines of the BMW 3 Series Sedan are designed for RON 98 fuel. The engines may be run on RON 95 and RON 91 fuel with a decrease in power and an increase in fuel consumption.
-----------------------------

For the German market they indicate RON 98. For the US market they indicate octane 91 occording to (R+M)/2 because that is generally how it is calculated here. I just checked my owner's manual and it definitely says (R+M)/2. Also the next time you fill up at the gas station look at the octane sticker and you will likely see (R+M)/2 underneath indicating that is how it was caculated. Not sure about any other countries.....forgot to add PON is the AVG of RON and MON or (R+M)/2.....

So you are saying E90Fleet was wrong! That's not possible, is it?

Based on that information, 91 octane fuel isn't actually high enough octane. In order to meet a requirement of RON 98 you would need a fuel with a PON 94 rating. They must say the requirement is only 91 octane because that is the highest octane fuel you can buy in some parts of the country. I wonder what the decrease in power/fuel economy is between 94 octane fuel and 91 octane fuel.

[canuck2]

Originally Posted by sdorn

Based on that information, 91 octane fuel isn't actually high enough octane. In order to meet a requirement of RON 98 you would need a fuel with a PON 94 rating. Interesting.

You may hear people complaining about the gas in california because 91 is the highest that the regular stations carry. As you may know Sunoco had a 94 PON but they are phasing that out from what I understand (was not available in my state). Supposedly much harder for them to supply with changes to fuel additive requirements....

[sdorn]

Originally Posted by canuck

As you may know Sunoco had a 94 PON but they are phasing that out from what I understand (was not available in my state). Supposedly much harder for them to supply with changes to fuel additive requirements....

Yeah, I saw that. There aren't any Sunoco's around here, though.

[speedyj88]

Originally Posted by shimshimhada

Do it. Be a man. Do the right thing.

You say I want the purse for $34.50. I say "noooo!". You don't get for $34.50, now price gone up, maybe $40. Be a man.

Haha, gotta love russell peters!

[e90rocks]

Originally Posted by kdan

u could siphon it out
let us know how that goes.

That was kinda mean.

[E90Fleet]

Originally Posted by canuck

OK - here is a clip from information on BMW's corporate site :

-----------------------------
The technical data specified applies to vehicles in the German market.

Max. output: the petrol engines of the BMW 3 Series Sedan are designed for RON 98 fuel. The engines may be run on RON 95 and RON 91 fuel with a decrease in power and an increase in fuel consumption.
-----------------------------

For the German market they indicate RON 98. For the US market they indicate octane 91 according to (R+M)/2 because that is generally how it is calculated here. I just checked my owner's manual and it definitely says (R+M)/2. Also the next time you fill up at the gas station look at the octane sticker and you will likely see (R+M)/2 underneath indicating that is how it was caculated. Not sure about any other countries.....forgot to add PON is the AVG of RON and MON or (R+M)/2.....

Its saying 98 RON is reccomended, but they can run on 91 RON, but you get reduced performance

US 87 is generally a bit higher than 91RON