ninjette.org - View Single Post - Bike done about 24000 miles, never a valve adjustment, feels weaker.

DannoXYZ · June 30th, 2018, 10:19 AM

Just for reference and future searches, people are often confused about octane ratings, how they're determined and their effects on combustion, Higher-octane fuels does not burn slower, in fact many of 100+octane fuels have 5-10% faster combustion speeds, which is what generates the extra power. What is "slower" in higher-octane fuels is formation of radical alkyl groups during combustion, which are initiators of knock/detonation.

Here's good dyno comparison: http://www.hotrod.com/articles/fuel-...ng-comparison/ Engine made identical power using 87-100 octane fuels, even with ignition-advancement to take advantage of higher-octane. Only 114-leaded race-fuel made an improvement of... 2%.

Anyway, octane ratings in Europe is based upon RON method. In U.S., octane = AKI = CLC = (RON+MON)/2. Fuel with 95-octane in Europe is about 89-octane at U.S. pumps, 98 in Europe is 91-92 U.S.

June 30th, 2018, 10:19 AM	#27
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Just for reference and future searches, people are often confused about octane ratings, how they're determined and their effects on combustion, Higher-octane fuels does not burn slower, in fact many of 100+octane fuels have 5-10% faster combustion speeds, which is what generates the extra power. What is "slower" in higher-octane fuels is formation of radical alkyl groups during combustion, which are initiators of knock/detonation. Here's good dyno comparison: http://www.hotrod.com/articles/fuel-...ng-comparison/ Engine made identical power using 87-100 octane fuels, even with ignition-advancement to take advantage of higher-octane. Only 114-leaded race-fuel made an improvement of... 2%. Anyway, octane ratings in Europe is based upon RON method. In U.S., octane = AKI = CLC = (RON+MON)/2. Fuel with 95-octane in Europe is about 89-octane at U.S. pumps, 98 in Europe is 91-92 U.S. Last futzed with by DannoXYZ; June 30th, 2018 at 12:56 PM.