The manual for the 954 recommends an octane of at least 86 or greater. Im sure it is the same for a lot of thebikes. 86or greatercan be purchased at any gas station that I can think of. Is it or would it be worth it to run an expensive gas purchased from the track like a 98 octane? I ride street, dont put in any track time or anything like that. Would I even notice anything from switching from the 91 I run now to a 98 unleaded? I have got a slightly modified bike nothing done internaly to the engine. Just a pipe, air filter and power commander. I dont know if it is important but my elevation is at about 5000ft.

 

we all know that the higher up you go the less air there is and if you run a higher octane thatn pump gas it requires a lot more air to do its job so if youre in a high elevation area then running 98 octane wont do you any good and not to mention the fact that it cost somewhere around $8-$12 a gallon right lol if im wrong then somebody correct me lol

 

he's right. The higher you get, the less oxygen you'll have. if a bike is speced at 105hp at sea level, it's surely not going to make nearly as much power at 5000 ft.

nope, you'll see a performance DECREASE if you use higher Octane fuels. high octane fuels come alive when you have high compression ratios and advanced spark timing, which require some detailed engine modifications.

 

Also the higher octane helps when your engine gets hotter. The higher the octane, the hotter it burns. Higher octane helps to prevent agianst "knocking".

Running 87, 89, 91 shouldn't be a problem. I wouldn't want to run race fuel unless you've got some good **** under your nuts.

 

can you provide a little more detail on the "higher octane helps when your engine gets hotter" thing?

okay so "Gas 101": octane = resistance to burn
so the higher octane = the more it takes to burn the fuel
thats where compression comes in, a high compression engine can burn that fuel efficiently. Sportbike engines have very low compression that are designed to burn ~87 octane. So logic says your trying to make an engine that will combust 87 octane efficiently try to burn a fuel of 10-12 octane higher. Again logic says that the engine will not be able to burn that fuel efficiently so if anything you'll lose power and waste gas. It takes quite a bit of engine work on a sportbike to get high enough compression to use high octane fuels.

I mentioned this in another thread but "race gas" and high octane gas are two COMPLETELY different things in the motorcycle world. Racers use fuels such as VP Racing's U4, MR9, MS103, etc. What makes them "race fuel" is that they are oxygenated and quite a bit more "pure" and "clean". They also don't have all the additives pump gas does for emissions, health,and other restrictions. The octanes for these fuels are actually in the neighborhood of 89. Nobody in their right mind would ever use this stuff on the street though, it costs a small fortune (anywhere from $10-20/gallon and you can't leave it in your bike without a good risk of eating your seals and hoses

 

Yeah for street riding anything higher than 91/93 premium is a waste. I run the cheap stuff in most of my bikes and never notice a difference even WFO.

 

Thanks a lot for the input! I kinda figured that for the type of riding I do that the pump gas would be just fine, especially considering the price of the high octane fuel.The pumpgas being 2.25 and the 98 octane being about 6.50 a gal.The thing that made me want to use it was the fact that it is possible to get it leaded and from what I understand that provides a type of lubrication for the combustion chamber and vavles.

 

woody....i'm thiking the higher octane helping when your engine burns hotter statement is likely for older engines with lots of carbon build up, raising the operating temperature within the chambers. lower octane gas, which the car was running fine on when new, is now predetonating cause of the increased operating temp. i've seen lots of old cars do this, like our old olds and camaro.

 

ahh that would make sense

 

Have a gander http://science.howstuffworks.com/gasoline3.htm. This will explain it all!