What Octane does your bike need?

[speedlimit85]

87 pinged

I rode 250 miles on Sunday. 87 in the tank engine pinged only in 5th gear accelerating at highway speed quickly. After hitting reserve, I filled the tank with 89 pinging went away under the same conditions.

[Bonz]

Nice input speedlimit85, thanks.

Motoman, in compression ratio the pure physical number (static CR, which is what we bat about when talking numbers) has nothing to do with the dynamic CR the bike experiences when all elements including spark timing and valve overlap enter in. I would suspect the ST 1300 takes premium because it has a fairly low redline which is indicative of not a whole lot of valve overlap (good for low end power), which boosts dynamic CR quickly despite not having an overly high static CR. My 2003 VStrom 1000 had an 11.3:1 CR and only called for regular 87 octane. Again, static or resting compression ratio figured by numbers on the calculator is only the beginning of the story.

On the ZRX1200, I bumped compression from a stock 10.0:1 to 11.0:1 static CR by addding ZZR1200 pistons (.5 bump) and removing the base gasket (the other .5 bump).

With the ZZR cams I already had in the bike I had lost some cranking compression because of the increased overlap. So despite the higher static compression ratio, it was offset by the increased overlap and I can still run the 85 octane gas. But my, what a midrange crush of power and top end flurry that pulls hard to the 11,500 redline compliments of the ZX11/ZZR1200 ECU and ZX11 double valve springs.

[willem.deboer]

Lowest octane available in Holland is 95 unleaded. It runs fine, but I have no comparison ....

[Bonz]

European octane is calculated differently than in the United States, someone may know what the equivalent would be. Thank you for posting from Holland!

[willem.deboer]

Thank you! EU RON 95 is the equivalent of US 91 octane.

[MaximPhil]

In North America we use a combined number. Explained here from the PetroCanada site.
Why is ethanol an effective octane booster?
The octane number written on the gas pump is Anti-Knock Index (AKI). It’s an average of two octane ratings using the same test equipment but using different operating conditions. The methods produce a Research Octane number (RON) and a Motor Octane Number (MON). Both were once considered important and that’s why AKI is an average of the two. With modern engines and fuels systems, recent studies have shown that RON is more important than MON. So in these cars, the higher the RON the better these cars perform. For an AKI rating of 91 the lower the MON the higher the RON. This difference is called sensitivity. All gasoline components have different sensitivity. Most hydrocarbon components have low sensitivity. Ethanol has high sensitivity and so, modern performance cars benefit from gasolines with ethanol. Why does ethanol have higher sensitivity? One reason is related to the cooler combustion that results from ethanol combustion. Higher knock tendency is directly related to higher combustion temperature.Here is a comparison of two fuels with different octane with and without ethanol.
91 Grade - no ethanol
RON 97.2
MON 85.6
Ultra 94 - with ethanol
RON 101.5
MON 88

Notice the difference in RON number from 91 grade without ethanol (97.2) and the RON of Ultra 94 (101.5). The difference is 4.3 numbers. That is significantly more than the 3 numbers difference between 94 and 91 AKI labelled on the pump. That is why gasoline with ethanol can be the best performance fuel for today's cars.

[MPittma100]

Corn Lobbyists

Would have us believe that ethanol is the best thing since sliced bread. It is, in fact, the best thing for the corn growers bank account. A study done during the Obama admin. Concluded that ethanol was not as good for the environment as was once believed.

15% ethanol was suggested and too many car makers stated that using this fuel will void the warranty. Only 2012 and newer cars are able to run E15. Where does that leave you?

Ethanol in gas is a "because you will believe anything" product.

You can run ethanol gas in your car and bikes, but be ready for so many more problems from ethanol if the vehicle is not run for a long period especially if carburated. Ask any RV dealer of your choice if it is true that 95% of all fuel related problems that they incur are ethanol related. Seriously, ask them.

[madmax-im]

I'm with you Mike...corn should be on my plate or in my moonshine ...not in my gas tank...I avoid using ethanol gas as much as is possible...Theres a non ethanol station 4 miles from me...

[donebysunday]

E10

has a shelf life, I found this true per my experience.
Can't remember where but a long time ago I heard 30 days and the E10 deterioration begins.
Could it be deterioration from absorption of moisture by the alcohol, when enough moisture is absorbed it over whelms the E10 to where it no longer is combustible ?
We use Heet here in the winter because the alcohol in HEET mixes with the moisture and lowers the freezing temperature keeping it from freezing and causing gas line freeze.
I have left E10 in an open container and noticed clear or colored globules (brown or greenish) in the bottom of the fuel. The HEET blended with the moisture and became heavier than the fuel then sank to the bottom.
Also this allows the moisture/condensation that entered into the fuel system to burn up during combustion.
This is not so bad if the fuel is used up fast, like riding year round or in the car filling up at least one or two times per month.
Then too just how old is the fuel when we pump it into our tanks ?
Just a thought ?

[pete_s]

I have to run 91 as it helps with ping uphill, accelerating, or load.

We have no non ethanol option in CT and the 10% rots alloy carbs bowls and jets with the water it picks up. So much that lawn mower shops sell no ethanol can gas by the quart to 5 gallons!

[donebysunday]

I have to run 91 as it helps with ping uphill, accelerating, or load.

We have no non ethanol option in CT and the 10% rots alloy carbs bowls and jets with the water it picks up. So much that lawn mower shops sell no ethanol can gas by the quart to 5 gallons!

I saw non-ethanol at a local mower shop being sold by the quart. They said this was very good fuel and worth the money, we don't want to know the cost !

[motoman]

I saw non-ethanol at a local mower shop being sold by the quart. They said this was very good fuel and worth the money, we don't want to know the cost !

...a wild guess: VP brand at $5.99quart.

[hamjam]

start using an ounce of Seafoam per gal of gas to clean all this stuff up
from the companys literature
When added to fuel, Sea Foam Motor Treatment helps to solubilize (disbursed micro bits) small amounts of moisture that can lead to corrosive fuel/ water mixtures or fuel line freeze ups. When solubilized, moisture in fuel will evaporate when exposed to intake heat.

Stabilizing fuel means to help fuel resist the oxidation and evaporation of petroleum hydrocarbons. Oxidized fuel, known as gum and varnish, is the most common cause of poor engine function. Unlike most other gas and diesel fuel stabilizer products, Sea Foam Motor Treatment is also a high-temp cleaner and upper cylinder lubricant – Sea Foam will dissolve gum and varnish that has ALREADY formed, overcoming lost engine power and function. More, Sea Foam resists fuel evaporation, adds petroleum lubricity and corrosion protection to engine parts, and will hold a fuel’s flashpoint over a long storage period. Sea Foam only contains highly-refined petroleum ingredients. It does NOT have harsh detergent of abrasive chemicals that can harm your engine.
I have been using it in all of my engines and i found that it does what it says and better than Sta-bil i just wish i could get it for its U.S. advertised prices

[XJOK2PLAY]

Bonz,
C14's have a factory warning sticker on their gas tanks that advise using a minimum of 90 octane.

I have, at times, ran 87 ethanol. If the temps are cool, I haven't noticed any pinging. But, temps ranging from the 90's or higher will cause it to ping under heavy acceleration. Doesn't do it using 91-92 octane.

I've also ran the 85 octane in Colorado with no ill effects. But, higher altitudes there, too.

Lots of variables can affect the result. Compression ratio, temp, altitude...
.... heavy right hand... Lol!

I'd think you need higher octane for that ZRX now...even at higher altitudes?
Bob

[donebysunday]

...a wild guess: VP brand at $5.99quart.

Can't say for sure what the price was but the store stopped selling it and put it on clearance for a price that was still crazy !
I remember seeing the clearance sign and checked the price (whatever that was?). I thought that stuff is still not going to sell.