08-07-2013, 05:09 PM
I just got around to reading this whole thread.
The difference in octane ratings (91 vs. 86) in the owners manuals is because the older manual is for the Australian model. They use the RON method of octane measurement. Here in North America we use the RON+MON/2 method, which results in a lower number for what is basically the same gasoline.
The CB11's relatively low compression ratio leads me to stick with Honda's recommendation. When I first bought the bike, I thought the slight ticking noise on hard acceleration might be detonation, so I ran a few tanks of premium through it. The sound turned out the be the EFI system working and the bike ran no differently on the higher octane.
My other vehicles are a little Nissan truck and a CB750. Both are supposed to run on regular grade. Unfortunately here in the desert, when it's 112 in the shade, intake temps above superheated asphalt can top 130. I've noticed that both the truck and the CB750 will detonate slightly under hard acceleration on our hottest days. As such, they both get 89 octane mid-grade from June through September and that fixes 'em up just fine. I haven't noticed a similar issue with the CB11 this summer, so it'll stay on it's usual diet of 87 octane unless something changes.
The difference in octane ratings (91 vs. 86) in the owners manuals is because the older manual is for the Australian model. They use the RON method of octane measurement. Here in North America we use the RON+MON/2 method, which results in a lower number for what is basically the same gasoline.
The CB11's relatively low compression ratio leads me to stick with Honda's recommendation. When I first bought the bike, I thought the slight ticking noise on hard acceleration might be detonation, so I ran a few tanks of premium through it. The sound turned out the be the EFI system working and the bike ran no differently on the higher octane.
My other vehicles are a little Nissan truck and a CB750. Both are supposed to run on regular grade. Unfortunately here in the desert, when it's 112 in the shade, intake temps above superheated asphalt can top 130. I've noticed that both the truck and the CB750 will detonate slightly under hard acceleration on our hottest days. As such, they both get 89 octane mid-grade from June through September and that fixes 'em up just fine. I haven't noticed a similar issue with the CB11 this summer, so it'll stay on it's usual diet of 87 octane unless something changes.