The Chinese, Research Octane Number (RON) is typically 4-6 octane higher than the R+M/2, Anti-Knock Index (AKI) used in the United States and Canada.
https://en.wikipedia.org/wiki/Octane...MON.2C_and_AKI
Therefore, a Chinese RON octane of 90 is roughly equivalent to a U.S./Canada AKI octane of 85.
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Spud
"Never argue with an idiot. He will drag you down to his level, and beat you with experience."
Mark Twain
2015 Zongshen ZS250GY-3 (RX3)
2006 Zongshen ZS200GY-2 (Sierra 200)
2005 Honda XR650L
2004 Honda CRF250X
1998 Kawasaki KDX220
Mods made to my Zongshen ZS200GY-2:
http://www.chinariders.net/showthread.php?t=6894