TimothyPilgrim wrote: > Funny, my motorcycle (1999 Honda CBR1100XX) has a ratio of 11:1 and it > runs on RUG-87. It also Compression ratio can't be the only factor in > determining octane rating required. >
Modern electronic ignition and fuel injection have allowed manufacturers to run higher compression with the same octane ratings without knock. Most modern engines have knock sensors and run right on the edge of pinging all the time, with the ECU dialing back the ignition advance when it sees the first signs of it.
