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I tried searching the forums and Google for octane preferences on the 765, but didn't get any hits. I've been using 87 (US), the manual says use "87 or higher"...I tend to spoil my vehicles so I was wondering what benefits, if any, would going with a higher octane provide (performance, longevity, etc.)?
 

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If the manual says 87, then in my opinion running anything else is a waste of money. The only reason to run 91 or 93 would be if your bike is tuned to take advantage of the timing changes. Running higher octane on a vehicle that doesn't require it does not give you more power. The best bet might be to get your gas at a top tier provider (e.g. BP but you can google others), apparently they put more/better cleaning agents in their gas.
 

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You'll get no benefit from running higher octane unless your motor has a knock sensor, so the computer knows when you have higher octane fuel and can advance the timing. My 2014 ST3 doesn't have one and I'm guessing the 765 is the same. I run 87 at the track, and it runs great.

My ST3 did seem to run better on pure gas (my manual recommends pure gas vs 10% ethanol but either is fine), but it wasn't worth going out of my way to get some.
 

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I agree with the others, from everything I've read it's not going to give you any benefits. I think the "Premium, Plus, Regular" naming conventions in the US are generally marketing ploys. Those typically refer to higher octanes which is the ability for the gasoline to resist combustion under compression vs the gas being "higher quality" which the naming conventions imply. That being said, "premium" at a specific company may have additional additives that their "regular" doesn't have but I'd be skeptical on what those additives benefits really are giving you.

The only car I've ever used more than the minimum is my current ride, and that's only because under the gasoline requirements it says "87 Octane, 89 recommended" so I use the 89.
 

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I've tested all grades available that you can put directly into a fuel tank 87-95 octane. The joys of living in Indianapolis, I can get race gas from a pump.. just has to go into a fuel container! My RS does not really enjoy any octane above 92 octane, it ran odd to be honest, sort of slow on RPM ramp-up. I stick to 91 and under, I am use to driving my truck 19mpg, so I don't mind mixing fuel grades. I tend to alternate octane levels every fill-up. I stick to Sunoco, Shell, and BP.
 

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Discussion Starter #7
I've tested all grades available that you can put directly into a fuel tank 87-95 octane. The joys of living in Indianapolis, I can get race gas from a pump.. just has to go into a fuel container! My RS does not really enjoy any octane above 92 octane, it ran odd to be honest, sort of slow on RPM ramp-up. I stick to 91 and under, I am use to driving my truck 19mpg, so I don't mind mixing fuel grades. I tend to alternate octane levels every fill-up. I stick to Sunoco, Shell, and BP.
Aside from 92+, any noticeable differences with the octanes you use in your RS? Why change around? Any benefits?
 

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Just like Skotyjones I run 91 in my RS. Haven't put anything else in the tank except for that. The guys at the shop recommended it when I told them that this bike only needs 87. Can't exactly remember how they put it, but basically because it's supposed to be a "performance" engine to give it a bit better from the bottom, and that it should also help to prevent pinks and knocks.
 

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The octane rating is simply a measure of how much compression you can subject the fuel to before it detonates. Higher octane won't help you if the engine is not designed to take advantage of it with advanced timing or higher compression - static or dynamic (forced induction). If the manufacturer states 87 or higher, that means the engine can reach maximum performance with 87. Higher octane than 87 will have no benefit.
 

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I run 87 octane with whatever percentage ethanol happens to be in it, and it runs perfectly. No knocking.

My Harleys, however, sound like pebbles in a tin can on anything less than 92 when I'm hard on the throttle.

Actually, now that I have almost 7000 miles on the Striple, on the now rare occasions when I pull out a Harley they sound and feel like they're falling apart anyway.
 

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I run premium fuel only in my direct-injection car and my 2010 STR even though the manuals say 87 is ok. Premium fuel has up to FIVE times more cleaners than regular which keeps the injectors clear and prevents detonation from lean mixtures. Also, with a compression ratio of 12.7:1 why not use the highest octane just to be on the safe side? BTW, premium fuel has the same energy as regular; the additives make sure that combustion takes place when it is supposed to and not before. All in all well worth it for an extra buck.
 

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I run premium fuel only in my direct-injection car and my 2010 STR even though the manuals say 87 is ok. Premium fuel has up to FIVE times more cleaners than regular which keeps the injectors clear and prevents detonation from lean mixtures. Also, with a compression ratio of 12.7:1 why not use the highest octane just to be on the safe side? BTW, premium fuel has the same energy as regular; the additives make sure that combustion takes place when it is supposed to and not before. All in all well worth it for an extra buck.
There is a myth (which might be true) that top tier gasoline distributors have a little more cleaners to keep deposits from clinging to the engine. That’s because higher octane is more or less a combustion inhibitor. If your bike or car is tuned take advantage of advanced timing, then yes, higher octane will be a benefit. But these additives are not there to increase combustion, that would negate the effect of taking advantage of advanced timing.

But if someone post dyno results of a bike with 87 and 93 octane and the higher octane makes a world of difference, then I will happily print out my post and eat it...!
 

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There is a myth (which might be true) that top tier gasoline distributors have a little more cleaners to keep deposits from clinging to the engine. That’s because higher octane is more or less a combustion inhibitor. If your bike or car is tuned take advantage of advanced timing, then yes, higher octane will be a benefit. But these additives are not there to increase combustion, that would negate the effect of taking advantage of advanced timing.

But if someone post dyno results of a bike with 87 and 93 octane and the higher octane makes a world of difference, then I will happily print out my post and eat it...!
You can rest assured this will never happen, so just let them eat their money buying useless higher octane fuel. :)
 

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...Premium fuel has up to FIVE times more cleaners than regular...
Would you mind citing a source or two for this assertion?

...the additives make sure that combustion takes place when it is supposed to and not before...
What additives are these? Octane would be the principle additive, and it's a combustion inhibitor. Higher octane fuel may have the same amount of energy in it, but the resistance to combustion caused by the higher octane makes it more difficult to extract. Are you saying other additives counteract the effects of the additional octane, to make higher octane fuel behave exactly like lower octane fuels?

I'm very confused.
 

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Would you mind citing a source or two for this assertion?



What additives are these? Octane would be the principle additive, and it's a combustion inhibitor. Higher octane fuel may have the same amount of energy in it, but the resistance to combustion caused by the higher octane makes it more difficult to extract. Are you saying other additives counteract the effects of the additional octane, to make higher octane fuel behave exactly like lower octane fuels?

I'm very confused.
He may be confusing premium in *brand* with premium in *octane*. Some premium brands of fuel claim to have more/better additives, and perhaps they put more of those into the higher $ high octane fuel, but that has nothing to do with the octane itself.
 

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True. I use 87, but always try to fill from a "top tier" company. Bike runs perfectly.
 

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He may be confusing premium in *brand* with premium in *octane*. Some premium brands of fuel claim to have more/better additives, and perhaps they put more of those into the higher $ high octane fuel, but that has nothing to do with the octane itself.

Shell being the only one I know. Only the premium grade has their proprietary additive.
 

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You can Google the gasoline of any of the fuel companies like Esso and they state on their websites that premium fuel (91 octane or greater) contain more cleaners than regular fuel and this is more appropriate for high-performance engines. Even though the 675 (with a 12.7:1 compression ratio) will run fine on 87 octane when new, IMO the premium fuel is better to use when the mileage gets higher and combustion chamber deposits build up. Holy crap, an extra buck won't even buy you a cup of coffee these days!
 
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