91 octane VS 87 octane

[Switchglide12]

Good evening you all, I am planning to ride my Niken GT from NJ to Alaska, if all goes as plan this summer. Question for you all,  have you used regular 87 octane on your bike? I am asking because on my cross country trip last year and year before, in some parts of the country you can only get 87 octane. You really had to look for specific gas station to find 91 octane. I never had to worry about this before because my BMW R1200 GSA only requires regular 87 octane gasoline, but Yamaha want 91 or better.  Since space is tight on the bike really don't want carry or try to look for octane booster while on the road. 

[PhotoAl]

I have filled up a couple of times with 87.  87 can be hard to find some places out west.  My 2020 Tracer Gt only had 300 miles on it the first time and the second time it had maybe 1,000 miles on it.  At 3,000 miles now and not problem - and I don't expect to see a problem.  My 2016 BMW F800GT saw a fair amount of 87 but said it required 91.  Never had a problem with it over the 26,000 miles I had it.  When running 87 I try and avoid lugging or high RPM Full throttle - in general avoid full throttle at all RPMs and particularly low revs.  Trying to avoid any operation that would cause pinging or preignition.  At the 600 mile service mentioned to one of the techs I had to run some 87 and he thought it was an absolute disaster - that is what he is supposed to say not sure it is based on reality - he said it was hard on the valves.  If I fill up with 87 will fill up with 91 at the first opportunity.  Generally on a long trip I don't run the tank super low and there is a 1/2 to 1 gallon left which will raise the average octane rating a bit.  If you are concerned could always carry some octane boost to add to the 87.  On a trip like that you will probably be carrying some additional fuel so you could always put the fuel in the tank and fill the rest of the way with the 87 then refill the spare fuel container with 87.  Next time you find 91 empty the fuel container into the tank and fill with 91.   Have always found it interesting where I coolant get 91 and again where it was available.

Have fun on your trip to Alaska, it's on my list of places to go.  

[betoney]

4 minutes ago, Switchglide12 said:

Since space is tight on the bike really don't want carry or try to look for octane booster while on the road. 

I primarily use premium 91 but I have used many tanks of regular 87 or 89 mid-grade with no adverse affects. 

A bottle of octane booster takes up as much room as a can of soda and will last several fill-ups (you wont need it for every fill-up) and if you run out, it is as common as brake fluid at every auto parts store you come across as well as Target, Wal Mart, most gas station mini-marts, truck stops, travel centers and probably Lowes/ Home Depot and farm supply stores.

[Ride On]

These engines don't burn down or suffer any ill effects from using 87 octane.  If they did you'd see threads and pictures of destroyed engines and burnt pistons.  Where are the dead engines?  There are none. 

If your engine doesn't knock, then you don't need higher octane, regardless of what the owners manual says.  It's that simple. 

And high octane gasoline doesn't help your engine last any longer.  Not one mile longer.  If there's no knocking then you're getting a normal combustion event.

I've got 13,000 miles on my FJ-09, mostly using 87 octane.  I use non-ethonol premium gasoline late season to run the ethanol out of the tank so it's ready for winter storage. 

The added benefit of using 87 octane is that it saves me about $0.80 per gallon.  I can use that savings to buy premium beer instead. 

 

[Switchglide12]

31 minutes ago, Ride On said:

These engines don't burn down or suffer any ill effects from using 87 octane.  If they did you'd see threads and pictures of destroyed engines and burnt pistons.  Where are the dead engines?  There are none. 

If your engine doesn't knock, then you don't need higher octane, regardless of what the owners manual says.  It's that simple. 

And high octane gasoline doesn't help your engine last any longer.  Not one mile longer.  If there's no knocking then you're getting a normal combustion event.

I've got 13,000 miles on my FJ-09, mostly using 87 octane.  I use non-ethonol premium gasoline late season to run the ethanol out of the tank so it's ready for winter storage. 

The added benefit of using 87 octane is that it saves me about $0.80 per gallon.  I can use that savings to buy premium beer instead. 

 

Thanks for the reinsurance. I did use 87 on all of my BMW's and owner manual did say 91 is required. I am sure I will not have problem with Yamaha using 87. In spring I will test out using 87 just to make sure I don't hear any pinging. If I do hear it, I pack some octane booster. 

[keithu]

10 minutes ago, Switchglide12 said:

Thanks for the reinsurance. I did use 87 on all of my BMW's and owner manual did say 91 is required. I am sure I will not have problem with Yamaha using 87. In spring I will test out using 87 just to make sure I don't hear any pinging. If I do hear it, I pack some octane booster. 

One thing to keep in mind is that the BMW might have had a knock sensor, but your Yamaha does not. A knock sensor detects pre-ignition which might be caused by lower-octane fuel, and the ECU can use this input to adjust ignition timing to compensate. So with a knock sensor you may perceive reduced power when running lower octane, but engine damage is less likely. BMW's boxers have knock sensors, but I don't know about the F800. 

The FJ-09/Tracer/Niken motor does not have a knock sensor. But like others, I've also run 87 octane a few times without any ill effects. I would definitely follow @PhotoAl's advice and avoid lugging the motor when you run it. 

[knyte]

Yep, it's alll about knock and knock prevention.  Keeping a bit of octane boost handy isn't expensive and won't take up much room.

[Skidood]

For what its worth, my SUV is supposed to receive premium, which is what I put in it.  If I fill with 87, it just doesn't run as nicely, its noisier, has less power and gets poorer fuel economy.  And it has the knock sensor and will retard the timing if it senses knock aka pre-ignition.  Octane and regular vs. premium is one of the most common topics on automotive forums next to regular oil vs. synthetic.

Hey, now that oil has come up, is the Yamalube regular or synthetic?  I would imagine that when I change the oil first time on my new GT, I will not think twice about using synthetic, I'm a firm believer....OK, verbal diarrhea episode completed.

[betoney]

10 minutes ago, Skidood said:

Hey, now that oil has come up, is the Yamalube regular or synthetic?

Yamalube has conventional, semi-synthetic and full synthetic available but for the price there are a lot of options that are at least as good if not better, no need to only consider Yamalube. 

[Ride365]

I'd run 87 in a pinch only......otherwise gonna always be 91 or higher.

[nhchris]

In theory the computer will sense issues created by low octane and alter operating parameters to compensate.  But...

I look at compression ratios as the ultimate indicator of what fuel grade is required.  At 11:1  and above I think 91 octane is indicated.

The Tracer 900 runs about an 11.5 to 1 squeeze.

And then there's this:  I am as cheap as the next guy when it comes to gas prices. But, when filling a tiny four gallon tank in a vehicle that gets 50 MPG I GO BIG and buy the highest octane juice they got!!!  Hey, Life is Short.

[Howton]

12 minutes ago, nhchris said:

In theory the computer will sense issues created by low octane and alter operating parameters to compensate.  But...

I look at compression ratios as the ultimate indicator of what fuel grade is required.  At 11:1  and above I think 91 octane is indicated.

The Tracer 900 runs about an 11.5 to 1 squeeze.

And then there's this:  I am as cheap as the next guy when it comes to gas prices. But, when filling a tiny four gallon tank in a vehicle that gets 50 MPG I GO BIG and buy the highest octane juice they got!!!  Hey, Life is Short.

Exactly! It's only an extra $2 per fill up.

[keithu]

2 hours ago, nhchris said:

In theory the computer will sense issues created by low octane and alter operating parameters to compensate. 

But on the FJ/Tracer it doesn't. This motor does not have a knock sensor. Without that input I don't think the ECU is able to detect and compensate for pre-ignition. 

[knyte]

1 hour ago, keithu said:

But on the FJ/Tracer it doesn't.

I searched around to see if Yamaha makes a Flex-Fuel engine, but a cursory search reveals nothing.

So, if it's not a flex-fuel engine, and no knock sensor, that means - for me, anyway - 91 octane as much as possible for best all around performance.

Sure, an emergency tank of 87 isn't going to kill anything...but it's easy enough to ensure 91 at all times.

[texscottyd]

8 hours ago, nhchris said:

Hey, Life is Short.

Premium fuel is the gateway drug to building a separate workshop just for your expanding collection of motorcycle projects.   

Don’t ask me how I know this...