since i've gotten the highest mileage of anybody that's posted so far as i've seen i'll continue running 93

btw the manual says one thing the bike another so i'll just run higher than both to be sure

 

Used to get around 180-200 per tank, some city, some freeway (always between 42mpg& 51mpg)Did the -1,+1 sprockets and I doubt I can get 130 miles per tank mostly city, but I haven't done the speedohealer, so I'm not entirely sure what it's getting now, But I'm sure it's down at least 10mpg.

 

I used to have 160-180 as high as 196 I think one time before the light came on. Then last season I put on some PP's and after that now I'm getting like 130.... I'm getting different tires for better milage.

Mike

 

Naw man...dem PP's be makin' U hit dem co-naz

 

There is so much misinformation in this thread it is disgusting. Too many people with no idea what they are talking about giving advice. I know this topic was about mileage. But I figure it would be good to address this.

As a engineer specializing in ICEs I figure I am qualified to talk. Yes octane is the resistance to burn... but not in the way people are implying. It is the resistance to autoignition. High resistance is desired! in a spark driven engine. So high octance engines have higher resistance to autoignition and faster flame fronts. Both are good. Higher octane gives you the potential for more power and will under no circumstances drain power if considering the same fuel. Running high ethanol (ethanol is an octane booster) will lower power but that is due to the lower energy content of ethanol. Lower mixes (10%) have been shown to improve emissions and without statistically significant impacts on power.

Faster flame fronts allows pressure to build up in the cylinder faster, allowing for more efficient energy transfer to the crank. Lower octane burns slower and will be building pressure into the downward movement of the cylinder. Due to the low octane, such fuels will autocombust (prespark) in high compression engines. Higher octane allows for higher compression, which enables for more energy to be produced by the engine. People in this forum are correct that running higher octane than designed will not neccessarily result in higher power output. It has a lot to due to the factor of safety used in the detonation calculation and the elevation of the engine.

Now the newer CBR600RR does have knock sensor, and I will only assume that the F4i does (I do not know for sure as I have never had a problem). If the knock sensor detects minor knock and retards timings, fuel economy will drop and power will decrease in order to protect the engine.

Now with regards RON and MON... RON is done on a variable compression engine and is about 10 higher than MON. MON is done on a variable ignition timing engine. Because US fuel is an average of the 2, pump gas is understated by about 5 octane. So 87 octane is about 91-92 RON. Which is why some places say 87 and others say RON 91. I normally put in 89, just out of safety because gas quality does vary and as many have said the cost is so minor on such a small tank. But there is no power loss and no damage to the engine by running higher octane. On a poorly maintained or higher compression engine lower octane will cause damage.

Thiago

 

So what you're saying is that even though my Bimmer asks for 91 I can use 89 because it's acutally 94?

 

Yes, but it depends on if the manufacturer is quoting RON figures or not. All of Europe and most of the rest of the countries in the world use RON figures at pumps. Europe has much higher octane values with regular being 95 RON which would be roughly equivalent to 90-91 octane here (R+M / 2).
A quick check on google reveals that for the M3 BMW recomments 98RON but the engine can run on 95RON. And for the 335i, 95RON is required.

So no, BMW already did the conversion and you need to put 91 in or ignition timings will be retarded.

 

Huh?

 

i got 290 kms to my last tank (still had 1.5L left in there when i refueled) for the US guys thats approx 170 miles..... best ive done on one tank.....

 

Just had another all time high for myself like 2 weeks ago 203miles then I filled up with like 4.4 gallons of gas in my 4.1 gallon tank. lol