Octane on our pumps is research octane + motor octane / 2
Our pump gas we require a lower Research octane number than in Japan (something to do with valve guides on older models and the additives we still use - In Japan folks are 'persuaded' to sell or junk their cars every 5-10 years. There are few old cars on the streets of japan.
We on average (exept methanol blends) have a max research octane of 98 and motor octane of 87
which gives about a 92 octane
In Japan however they use a max research octane of 100 and have a motor octane of 88.
Giving what we would call an octane of 94 .. yes I was wrong with that 87 guess.
All that matters is that it is higher, octane makes a big difference on performance above 10:1.
Here are the engine specs.
http://www.geocities.com/MotorCity/P...neEngines.html
Note there are two 170 HP 4age's on this page one they note is a jap spec 4agze the other is a VVti 4age but they have a pic of the dyno run, that happens to have Japanese written all over it.
As for japanese fuel vs ours and car performance...
http://www.hondatuningmagazine.com/f...11ht_delivery/
http://www.spdusa.com/driving_the_wrx_engine.htm
How much can changing octane affect performance?
Read that in the following about 12 octane points will double the horsepower that's a 100% gain.
http://sdsefi.com/techocta.htm
( I interpolated that number btw but I think it is accurate)
Ya but its only 2 octane points you say can it really make that much of a difference??
If 12 octane points is 100% then 2 octane points should be good for about 17%
17% of 145 is 24HP
145 + 24 = 169
Pretty damn close if you ask me.
Maybe the anti knock sensor is kicking in on those cars you mentioned and tweaking back the timing or playing withthe fuel/air mix ask them to run some race fuel for a week and see if they notice a difference.