there seems to be a misunderstanding on octane and what it means so i thought i would post some links to clear this up and help out some of those who are hurting their cars performance instead of helping it. this has come up quite a few times in various threads just this year so here you go folks. if you have anything to add please make sure it is factual, not what you think.

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

http://www.howstuffworks.com/question90.htm

 

thanks for the info jeremy, (so you tring to leave us now huh? ADVERTISE HERE HELP JEREMY GET AN FD )

peace

 

question: the first link says that octane is the ability to prevent engine knock under pressure... how much pressure builds up in a rotary engine?

 

One more thing to note. At see level, the air pressure is approx. 15.7 psi, not considering any barometer changes because of thunderstorms, hurricanes, or any other meteorlogical effect that mother nature throws at us. Up at high altitudes like Denver, the lowest available octane rating is 85. Thats the same as 87 at sea level but they take into consideration the density of the air. Its not 15.7 psi @ 5280ft. Same reason why John Force runs 4.94 in Englishtown NJ and 6.1 in Denver. Less air/fuel mixture means less power. Anyway, the point I'm getting at is that if your car manual says its best to use 87 octane, and you live up where you can throw a rock at the moon and hit it, its ok to use 85.

 

pressure refers to your compression. the compression on 12a's and the first 13b's were not really high, thus why the run better on 87octane. I believe that all commercially available rotaries that weren't turboed had a compression suited for 87octane. turbo charging, however, raises the pressure before compression and will need a higher octane to keep from detonating.