Prem fuel? and question of octane rating at altitude

[markjenn]

To my knowledge, this motor does NOT have any knock sensors. I don't believe this motor has ANY ability to adjust timing with regards to pre-ignition.

I think we've confirmed this a while back. (One of the areas I wish Yamaha hadn't been so ruthless in trying to keep costs down. A brand new design FI'ed engine deserves knock sensors.)

I'm with you; I would never routinely consider running lower-than-spec'ed fuel in any engine without knock sensors.

- Mark

 

[caveman]

The tank sticker here in OZ clearly states to use 95 octane (ROM) at all times. How does this compare to the tank sticker for you "yanks"
Not sure how the interpretation of the word octane varies from one country to the next.

 

[markjenn]

The tank sticker here in OZ clearly states to use 95 octane (ROM) at all times. How does this compare to the tank sticker for you "yanks"
Not sure how the interpretation of the word octane varies from one country to the next.

You are on the "Research Octane Number" (RON) system as is most of the world outside North America. There is another commonly used octane system called "Motor Octane Number" (MON) which uses a different test method and typically measures the same gas 8-9 points lower. In the USA, we use "pump octane" which is the average of the two - you see the notation of (R+M/2) on the pump to indicate this.

Net, net, typically US pump octane is about 4 pts lower than RON. IOW, your 95 RON is about the same as our 91 pump. Which is exactly why Yamaha specs 91 pump in the US manual.

- Mark

 

[caveman]

Thanks Mark. Makes a lot more sense now. Another conversion to make along with the metric system and the fact you guys are allowed to ride on the wrong side of the road. Life would be boring if we all did it the same way I suppose.

 

[MidlifeMotor]

I like to take the "dumb man's" approach to this topic. When I stop at a station, I put in the highest octane offered. I start my bike and ride away. ::021::

 

[snakebitten]

I like to take the "dumb man's" approach to this topic. When I stop at a station, I put in the highest octane offered. I start my bike and ride away. ::021::

Me too.
But I had the good fortune of riding cross country in Australia on an S10 and he is right about the much higher octane numbers. AND the pumps have no method to pay.


By the way, its actually easy to adjust to the "other side of the road" in traffic. Just follow someone. But so much of the countryside is sparsely populated and I found many fantastic roads that another vehicle would not be seen for a long time. Had to fight off the tendency to revert back to instinct. Road signs would get me back on track.

 

[MidlifeMotor]

By the way, its actually easy to adjust to the "other side of the road" in traffic. Just follow someone. But so much of the countryside is sparsely populated and I found many fantastic roads that another vehicle would not be seen for a long time. Had to fight off the tendency to revert back to instinct. Road signs would get me back on track.

I find it easier to ride right down the middle, no matter what country I am in. Screw em.

 

[bikerdoc]

I find it easier to ride right down the middle, no matter what country I am in. Screw em.

um, but you better be careful you might blur the "lines" and cross the "line" and be ticketed (PUN intended) ::024:: ::025::