98 RON Fuel - Does it exist in the states?

[Johnny_B]

I live in Sacramento and have an '05 12RT. When it comes to fuel, the best I can find is "supreme" which is usually only 91 octane. The bike runs well with this but I have always wanted to try it on the max. Does anyone know where you can buy fuel with higher octane? Is there an additive that might work?

 

Thanks,

[Urban Surfer]

You can buy an octane boost at nearly any automotive supply shop. Try STP 104 octane boost, you can mix it at a lesser rate. I used to use it in a Yamaha I had. When I was running the bike hard(which was most of the time) it ran silky smooth.

[ShovelStrokeEd]

Go to the local drag strip. They will have 100 or 105 octane unleaded race gas. They will not let you put it in your tank. You will have to bring a container. Try not to faint when you find out the price.

[Paul Mihalka]

Go to the local drag strip. They will have 100 or 105 octane unleaded race gas. They will not let you put it in your tank. You will have to bring a container. Try not to faint when you find out the price.

And it won't do you, or your bike, any good...

[John Bentall]

European and US Octane Ratings are different.

If you read this thread, it will explain .

http://bmwsporttouring.com/ubbthreads/sh...true#Post588560

[HairyCannonball]

The only reason to use a higher octane fuel is if you have a pinging problem. Even though the R12RT has knock sensors you will still hear it ping once or twice then noticeably feel the timing retard. I notice no pinging at all even on mid-grade fuel although I will on low-grade, and if this isn't happening then you don't need higher octane fuel. Remember also that in the US gas is usually rated by the (R+M)/2 method which gives a lower number than RON. I would bet the 91 you are finding is 91 (R+M)/2 which is roughly 97 RON.

 

Tim

[Pictou]

There apparently is also a perfomance penalty. I saw an article in a British motorcycle mag on the 1200S. With 98 RON fuel it made 8 HP more than when run on regular (dynoed at 140 HP on 98 and 132 HP on regular). The knock sensors may keep it from knocking but they also keep it from producing maximum power as well.

 

The only reason to use a higher octane fuel is if you have a pinging problem. Even though the R12RT has knock sensors you will still hear it ping once or twice then noticeably feel the timing retard. I notice no pinging at all even on mid-grade fuel although I will on low-grade, and if this isn't happening then you don't need higher octane fuel. Remember also that in the US gas is usually rated by the (R+M)/2 method which gives a lower number than RON. I would bet the 91 you are finding is 91 (R+M)/2 which is roughly 97 RON.

 

Tim

[HairyCannonball]

There apparently is also a perfomance penalty. I saw an article in a British motorcycle mag on the 1200S. With 98 RON fuel it made 8 HP more than when run on regular (dynoed at 140 HP on 98 and 132 HP on regular). The knock sensors may keep it from knocking but they also keep it from producing maximum power as well.

 

The only reason to use a higher octane fuel is if you have a pinging problem. Even though the R12RT has knock sensors you will still hear it ping once or twice then noticeably feel the timing retard. I notice no pinging at all even on mid-grade fuel although I will on low-grade, and if this isn't happening then you don't need higher octane fuel. Remember also that in the US gas is usually rated by the (R+M)/2 method which gives a lower number than RON. I would bet the 91 you are finding is 91 (R+M)/2 which is roughly 97 RON.

 

Tim

 

As I said, if you read carefully, it will ping a couple times then the knock sensors will cause the timing to retard. I have heard it, and I have felt it when using lower octane fuel. It is readily apparent when riding and you can easily feel the performance loss. BUT!!!unless it is doing this, higher octane fuel will cause no performance increase. Also the 98 RON fuel you mentioned is roughly equivilant to a (R+M)/2 of ~92. Most pumps in the USA publish the (R+M)/2 rating. The octane needed is also dependant on the altitude you are running at.

 

Tim

[Johnny_B]

Ah. That makes sense. I will study up on the difference between the ratings. I know about the knock sensors and the adjustment to the timing. I just thought that maybe the bike was retarding the timing all the time because of the fuel grade. I guess that's not the case. Thanks for the replies and the links.