[mossdahaus]

I just got done reading on Rogue that Dan Kyle GAINED power (1-2hp) by using 87 over the 93. I was just wondering if anyone has done this?


"3. In testing various grades of pump gas I consistently found that 87 octane fuel makes 1-2 more horsepower than those exact same bikes ran on Premium 93 octane. We tested five liter class motorcycles (97 CBR900RR, 02 Honda 919, 2000 RC51, 2000 GSXR750 & an 02 R1) & only the R1 seemed unaffected by the octane of the fuel. Now I am certainly not going to tell you to run less than the recommended octane (92) in your RC51 as the specific needs of the motor dictate that a higher octane fuel is needed, but the results are blatant in that more octane does not mean more power.
It is only fair that I note that when testing the pump gas on some of the 600's (Yamaha R6 & the GSXR600) the inverse was true in that they did lose a little horsepower on the 87 octane vs the 93 octane. Most likely because of the higher compression ratios of the smaller motors, however the CBR600F4i gained a little horsepower."

[Big Kahuna]

Discussion on HP gains from octane level is one of those topics that can get ugly really quick. I've always heard that it's best to run lower octane if possible as it burns hotter and produces more HP. You'll need to run the higher octane if your car/bike pings when using the lower octane do to pre-ignition.

I usually run 87 and throw in a tank of 91 Chevron (with techroline) in there every once in a while. Run the same in both the '98 900RR and the '05 1000RR.

[Big Kahuna]

I also run 87 in my '95 Honda Passport and '05 Nissan Altima with no noticeable ill affects.

[fl-929]

Run what the manual says too. Most Honda's say 87. If the engine pings then move up in octane.

[-Z-]

Originally Posted by fl-929

Run what the manual says too. Most Honda's say 87. If the engine pings then move up in octane.

Yeah, and if the engine pings or knocks, then you gotta ask yourself, why? Before you start blaming the octane or the manufacturer, look at what mods you've done first.

[MelScrilla]

i always run 93 in my RC because they reccomend no less then 92

[TheEngineer]

I've never run anything less than premium (92+). From a chemical combustion point you have less filler materials in your fuel. These will burn less cleanly and cause more carbon build up on your valves and in your cylinders.

[Solman]

Originally Posted by -Z-

Yeah, and if the engine pings or knocks, then you gotta ask yourself, why? Before you start blaming the octane or the manufacturer, look at what mods you've done first.

With the possible exception of the PCIII, MOST mods that we'd perform wouldn't make any difference to octane requirements or performance. The octane number is a rating of the detonation characteristics of the fuel. Higher octane equals more heat required to burn. It can be used in higher compression engines with less chance of premature ignition. The PCIII can change our air/fuel maps and the R model can change the timing so the octane requirements MIGHT be altered. Other than head/bottom end work or adding turbos/NOS which will change internal engine behavior, the factory recommended octane is the one you should probably use.

[nedro]

Originally Posted by TheEngineer

I've never run anything less than premium (92+). From a chemical combustion point you have less filler materials in your fuel. These will burn less cleanly and cause more carbon build up on your valves and in your cylinders.

Higher octane has more additives.