Hello fellow riders,
I do a lot of reading on this forum and this just happen to catch my eye.
I've always used high-grade fuel as I've heard (text and TV) that any engine with compression over 9.x (something, can't remember the exact number) requires high octane fuel to avoid pinging. This is because the high-octane fuel is less volatile and will not pre-ignite before spark/ignition due to high compression... This may be true or not.
BUT....
What I have noticed is that almost everyone who uses 'regular' octane fuel says it's because the manual or Yamaha says to. This brings me to the 'NOTE' in the owner's manual. I've pasted it below:
First is says:
Recommended fuel:
REGULAR UNLEADED GASOLINE
ONLY
Fuel tank capacity:
19.4 L (5.13 US gal) (4.27 Imp.gal)
Fuel reserve amount:
3.6 L (0.95 US gal) (0.79 Imp.gal)
Which makes me think regular-octane fuel... right?
Then right below this it says:
Your Yamaha engine has been designed
to
use regular unleaded gasoline
with a research octane number of
91 or higher. If knocking (or pinging) occurs,
use a gasoline of a different brand
or premium unleaded fuel. Use of unleaded
fuel will extend spark plug life
and reduce maintenance costs.
Being that it says a RON of 91 or higher, this means high-octane fuel.
I believe this section was added specifically due to different octane numbers in different states. Here in Florida, we have as follows:
Regular: 87
Middle: 89
High: 91/93 (depending on where you go)
So what I get from this is.. It doesn't matter what 'level' of fuel you use, as long as it's a minimum of 91. So to all of the people who use 'regular' fuel that is 87 octane (because Yamaha says so and they know what's good for the bike), you may not be using what is recommended after all.
Let me know your thoughts on this as I'm curious to see what people this about my reasoning on this.
Thanks!
-Kyle