[pw4]

With my 230i just a few days away, I've been studying the owners manual (yes, I do that sort of thing).

Checking fuel type, I came across this (P314): "The power and consumption specifications refer to operation with RON 98 E10 fuel." Now I'm wondering if that results in the conservative power figures BMW is known for, if people instead run on RON 98.

To be even weirder, the required petrol grade (P315) is RON 95. Why would you measure power and consumption on something other than the required grade of fuel?

(In Australia we have a choice of RON 91, 95, 98 or RON 94 E10. So I'll be using RON 95.)

[RockCrusher]

Originally Posted by pw4

With my 230i just a few days away, I've been studying the owners manual (yes, I do that sort of thing).

Checking fuel type, I came across this (P314): "The power and consumption specifications refer to operation with RON 98 E10 fuel." Now I'm wondering if that results in the conservative power figures BMW is known for, if people instead run on RON 98.

To be even weirder, the required petrol grade (P315) is RON 95. Why would you measure power and consumption on something other than the required grade of fuel?

(In Australia we have a choice of RON 91, 95, 98 or RON 94 E10. So I'll be using RON 95.)

Would have to make a guess BMW chose to use 95 instead of 98 due to 98 (my WAG) not being as available.

On a related note my Porsche cars were spec'd to use 93 but Porsche when it was getting the cars/engines approved for sale in the US used Chevron 91 (E10). 93 with or without ethanol is pretty scarce in the US.

Some years ago I did have a chance to run 93 in my Porsche 996 Turbo -- this in Wyoming -- which up until that time I could only fuel the Turbo with 91 E10 (I lived in CA at the time). With 93 the engine perked up quite a bit. And this despite the altitude (~8000 feet above sea level).

In the US where I live now -- no longer in CA -- I have had a chance to try both 91 E10 and 91 ethanol free -- 91 AKI which I think is equivalent to 93 RON -- and while I have not dyno'd my 230i my butt dyno can't detect any difference.

This has been the case with my Dodge Hellcat, M-B cargo van, Dodge Scat Pack, BMW 230i, MINI S, MINI JCW, and now my BMW M2 all of which have been fueled with 91 E10 and 91 ethanol free.

Also, I have not had a chance to try a higher octane grade of gasoline. 93 which for here would be the next level of octane above 91 because 93 is not available here.

Bottom line I think you (the engine) will be ok with 95 RON. You are of course free to try a higher octane of gasoline and if you can find it ethanol free and see if the engine runs better. If it does then you can stay with the higher octane of gasoline and the ethanol free stuff if the cost and availability suit you.

For 91 ethanol free I pay a few cents more per gallon but given my low annual miles driven the few cents doesn't make a difference. And the station that sells ethanol free is very convenient and is easier to get into and out of than the two other stations which sell only gasoline with ethanol.