Fuel octane explained.

[Easy Rider]

Do you think the anti " knock " feature is activated right after the engine is fired ??? .....

There is no "anti-knock" feature......and there is not "octane detector" either.

What there IS is a knock detector.
When it detects a knock, it retards the spark a bit.

IF.....the knock occurs BEFORE the spark hits due to insufficient octane rating of the fuel.......the knock-detector-spark-retard does NOTHING to help that. This is why having sufficient octane is so important.

But yes, if your riding habits don't cause any knock or ping in your engine that you can hear, you probably will be OK.

It is possible, however, that the ping is there and you just can't hear it. If that is the case, the knock detector will retard the max. spark advance a bit and result in slightly reduced performance......and the ping will still be there.

 

[Easy Rider]

Via the very same "knock sensor" you mention as it WILL cut timing with lower octane....

Not unless there is a knock detected it won't.

 

[Easy Rider]

the pressure from compression by itself is not enough to cause detonation.

Our Spyders are not suffering from pre-ignition.

It's all a matter of timing.

As you pointed out, pre-ignition and detonation are not the same thing.

The heat and pressure of compression CAN cause pre-ignition in almost any engine.
How FAR ahead of the desired ignition point it occurs determines how bad the result will be.

Without some sophisticated equipment you can't really tell if there is a "slight" pre-ignition present or not.

While it would take some unusual circumstances to make it happen, if the pre-ignition occurred way too early damage can result similar to detonation. Like trying to burn gasoline in a diesel engine, for example.

 

[BLUEKNIGHT911]

ANTI-KNOCK

There is no "anti-knock" feature......and there is not "octane detector" either.

What there IS is a knock detector.
When it detects a knock, it retards the spark a bit.

IF.....the knock occurs BEFORE the spark hits due to insufficient octane rating of the fuel.......the knock-detector-spark-retard does NOTHING to help that. This is why having sufficient octane is so important.

But yes, if your riding habits don't cause any knock or ping in your engine that you can hear, you probably will be OK.

It is possible, however, that the ping is there and you just can't hear it. If that is the case, the knock detector will retard the max. spark advance a bit and result in slightly reduced performance......and the ping will still be there.

Please forgive :banghead::banghead::banghead: :bowdown::bowdown::bowdown:...... I meant to say .....PRO-KNOCK :roflblack::roflblack::roflblack::roflblack::roflblack:............ Mike :thumbup:

 

[PaladinLV]

1. You forgot the MOST IMPORTANT word used PRIOR to the quote: "Use premium unleaded gasoline with an AKI (RON+MON)/2 octane rating of 91, or an RON octane rating of 95," and that word is RECOMMENDED.

4. "To those who run on "Regular" gas: your engine will knock." That is an inaccurate statement as written. It should state, To those who run on "Regular" gas: your engine MAY knock.

I use regular 90% of the time, and NEVER have experienced knocking.

6. There is no EMPIRICAL data that show the use of a lower octane fuel will DAMAGE the 1303 engine! Performance "MAY" be downgraded. I might add I have used Regular in Harley's which also "recommend" 91 and again ONLY performance MAY be altered. No manufacturer to my knowledge has ever stated lower octane will "damage" an engine.

With 52 years of riding, I have never seen so many "obsessed" about such inconsequential stuff as in the Spyder Community.

Each rider must determine for themselves what is best for them and their environment; whether that be tires, tire pressure, oil type and changes, battery life, brake pads, a couple of drops of oil on the pavement, the noise of the fuel pump, the noise of the air suspension, etc. Awareness is a necessity, but people need to WORRY LESS and ENJOY MORE.

Happy New Year!

AJ

Before Spyders are made electric we have to deal with gasoline. It's dirty, it smells and it's way too complicated. I never liked chemistry anyway.
I've seen too many erroenous threads and posts here to remain quiet, so here's everything you need to know about "Premium" vs "Regular" gas and which one is right for you.

Long Story Short (very simplified):

1. Modern Spyders run on Premium Gas, or for USA: octane rating of 91 (it's different in every country).
Here's from the owners manual: "Use premium unleaded gasoline with an AKI (RON+MON)/2 octane rating of 91, or an RON octane rating of 95". (See your owner's manual)
Yes, you can run your Spyder on lower octane fuels, but it comes at a cost (see #4)

2. This has nothing to do with how one grade burns hotter than another (it's the same), or how "Premium" is better than "Regular" (it's not)

3. The ONLY reason for this octane requirement is the engine compression ratio. That's it. Nothing more, nothing less. It's all about compression. Simple physics and chemistry.
Higher octane fuels resist to self-combustion due to the heat of the compression. The higher the engine compression, the higher the requirement for octane. Spyder engines have a very high compression ratio (12.2:1 for twins and 12:1 for triples) Any engine with compression over 11:1 has to have a "Premium" gas.
NOTE: I only looked up compression of modern Rotax engines. Yours might be different.

4. To those who run on "Regular" gas: your engine will knock. Here's what you need to know: "Burning fuel with a lower octane rating than that for which the engine is designed often results in a reduction of power output and efficiency. Many modern engines are equipped with a knock sensor (a small piezoelectric microphone), which sends a signal to the engine control unit, which in turn retards the ignition timing when detonation is detected. Retarding the ignition timing reduces the tendency of the fuel-air mixture to detonate, but also reduces power output and fuel efficiency.

5. "Premium", "Supreme", "Plus" and "Regular" terms are completely bogus and misleading. It's all the same gasoline. In fact, most of the gas stations use the same refineries. The difference is in additives. In simple terms: higher octane gas has more expensive additives and lower octane has cheaper additives. "Plus" grade gas is just a mixture of "Regular" and "Premium".

6. A more expensive, high octane fuel does absolutely nothing for the engine designed to run on lower octane fuels, however, a low octane fuel will damage or degrade performance and fuel economy of the engine designed to run on a high octane fuel.

If you want to know more, here's a good video: https://youtu.be/WYlk9C1o0nk
(I'm not affiliated with them in any way)

I hope this helps

 

[Bob Denman]

 

[Sarge707]

I use Shell 93 Because Nothing else is Good Enough for the Yellow Bumble Bee!:yikes:

 

[Easy Rider]

Awareness is a necessity, but people need to WORRY LESS and ENJOY MORE.

:thumbup::thumbup::thumbup::thumbup:

 

[BajaRon]

1. You forgot the MOST IMPORTANT word used PRIOR to the quote: "Use premium unleaded gasoline with an AKI (RON+MON)/2 octane rating of 91, or an RON octane rating of 95," and that word is RECOMMENDED.

4. "To those who run on "Regular" gas: your engine will knock." That is an inaccurate statement as written. It should state, To those who run on "Regular" gas: your engine MAY knock.

I use regular 90% of the time, and NEVER have experienced knocking.

6. There is no EMPIRICAL data that show the use of a lower octane fuel will DAMAGE the 1303 engine! Performance "MAY" be downgraded. I might add I have used Regular in Harley's which also "recommend" 91 and again ONLY performance MAY be altered. No manufacturer to my knowledge has ever stated lower octane will "damage" an engine.

With 52 years of riding, I have never seen so many "obsessed" about such inconsequential stuff as in the Spyder Community.

Each rider must determine for themselves what is best for them and their environment; whether that be tires, tire pressure, oil type and changes, battery life, brake pads, a couple of drops of oil on the pavement, the noise of the fuel pump, the noise of the air suspension, etc. Awareness is a necessity, but people need to WORRY LESS and ENJOY MORE.

Happy New Year!

AJ

I agree that no one should be 'Obsessed' about this subject. Everyone should use whatever octane, brand, etc., they choose. But being informed can help with that choice.

The truth is that your Spyder will never 'Knock' (which is a pre, or early ignition in the cylinder). This is because the computer on your Spyder will compensate for just about any octane deficiency. When the computer senses a knock situation it will retard the ignition timing (when the spark plug fires) as much as needed to prevent knock. Although this is not ideal and you will lose a certain amount of power and performance. It is much better than having the engine knock. This is one reason it is important to use Thermal Paste (not Anti-Seize) on your spark plug threads. Thermal paste helps keep the spark plug from overheating and creating a knock situation.

Before computers were able to compensate, pre-ignition or knock was a potentially devastating possibility. Here are some results of knock. But I want to re-emphasize that this WILL NOT HAPPEN to your Spyder regardless of what octane you use.

 

[Easy Rider]

When the computer senses a knock situation it will retard the ignition timing (when the spark plug fires) as much as needed to prevent knock.

Before computers were able to compensate, pre-ignition or knock was a potentially devastating possibility.

Retarding the timing WILL NOT prevent or correct "pre-ignition"......because by definition that occurs BEFORE the spark happens.

If an unusual set of circumstances causes the fuel mixture to pre-ignite......like low octane, lean mixture, high engine temp and a sudden heavy load......then it still can be "potentially devastating" and the computer can do nothing to stop it.

NOW.....having said that......it is possible for a sophisticated engine control system that includes electrical variable valve timing to compensate for something like that, but you won't find that feature in a Spyder.......and not in most normal car engines either.

Although they seem similar, pre-ignition and "spark knock" are two entirely different things.

 

[jcthorne]

Retarding the timing WILL NOT prevent or correct "pre-ignition"......because by definition that occurs BEFORE the spark happens.

If an unusual set of circumstances causes the fuel mixture to pre-ignite......like low octane, lean mixture, high engine temp and a sudden heavy load......then it still can be "potentially devastating" and the computer can do nothing to stop it.

NOW.....having said that......it is possible for a sophisticated engine control system that includes electrical variable valve timing to compensate for something like that, but you won't find that feature in a Spyder.......and not in most normal car engines either.

Although they seem similar, pre-ignition and "spark knock" are two entirely different things.

Just as an FYI, this sort of engine control to prevent pre-ignition in high boost applications is exactly the patented tech that is know as Eco-Boost from Ford. Its managed by a combination of direct fuel injection timing and computer control EGR used as an ignition suppressant much like water injection once was. This is why Ford's high boost and relatively high compression Eco-Boost engines all run just fine on the recommended 87 octane fuel. All other turbo engines from other manufactures require premium fuel. Toyota and a few others have paid to licence Ford's engine control tech but I do not know of any that have brought it to market.

 

[gom]

What octane should you use in your bike

I have seen a lot of wrong information on what octane we should be using in our spyders and also people using higher or lower octane than what they are suppose to be using per the manufacture spec's so here is a web site to go to and find out the truth about it. https://www.meineke.com/blog/using-premium-gasoline-really-save-money/. Hope this helps

 

[trikermutha]

87 or above for me works

 

[Batmobil-F3]

In Germany we have petrol with the following octane numbers (AON = Average Octane Number): Type "Super" with 90 and "SuperPlus" with 93. Spyder riders refuel "Super". Before 2011 we still had "regular petrol" at 87, but this no longer exists today.

 

[Daddyray]

I use premium gas only. The thing I have is I get my gas from Costco which has a savings of usually 15 to 30 cents a gallon or more. Around me Bj's and Sams also hold to almost the same price as Costco. This is more of a fyi as to where to get gas if you have the possibilty to do so in your area.

 

[AY4B]

Premium around here is 93 octane. I use premium unless I can get by Buc-ee's and get their ethanol free regular that is 92 octane. It is priced just a couple of pennies more than their mid grade.

 

[JayBros]

For those who believe BRP and other vehicle manufacturers are in cahoots with big oil, use whatever floats your boat. Until I accumulate enough scientific information that makes me smarter than the engineers who designed the Spyder engines I'll use what they recommend. And no, when on tour and I have been unable to get anything but 87 I can't tell any difference in the way the engine runs or the mileage I get, but that's an unusual, not routine situation. If I couldn't afford the recommended fuel, I wouldn't have bought the Spyder.

 

[ARtraveler]

The information will be all over the place.

Early Spyders said to use at least 90 octane. For years, I did. Paid 30 - 40 cents per gallon higher for the higher octane.

Bottom line now, for the last THREE years I have been using 87 octane in all my vehicles. Car, Kawasaki, and two Spyders. I do not notice any lack of performance in either Spyder. I believe the computer compensates.

I may not be perfectly right...but it is working for me. And now, I am using the 10% ethanol that is common here in AR. Still no difference, IMO.

 

[glorybiz]

I have always used 93 octane in all my motorcycles and lawn equipment as I never wanted to have a fuel issue with them sitting over the winter

 

[Chupaca]

Well....

Nothing lower than 87.... I run higher but mostly for the additives the price difference is minimal. We have designer fuels....:roflblack: summer blends, spring, fall and winter along with weekend special blends..:roflblack::roflblack: gotta love this state....