To Super, Or Not To Super : That Is The Question

[jefflthomas]

So what’s the downside of using too high an octane fuel? Higher cost with no benefits is one. Paradoxically, another is that burning higher octane fuel in an engine designed to operate at a lower octane rating can produce carbon deposits secondary to partially unburned (slower burning) fuel. These carbon deposits can build up so as to reduce combustion chamber volume and effectively raise your compression ratio, causing you to actually need a higher octane grade.

http://www.ducati-upnorth.com/tech/octane.php

due to the difference in international methods of rating octane content i'm just going to call it Regular & Super

my stock ZRX1200 engine is designed to use regular gas, but due to storage issues i use both

i use regular in the Spring, Summer & early Fall

but as the only ethanol free gas available to me is Shell V-Power i switch to super in the late Fall for storage considerations

i also pre-mix the super with a fuel stabilizing product (Klotz Octane Booster) that raises the octane by 2 1/2 numbers ....

so its super duper gas...LOL

btw...i intentionally rev out the motor often while using the super & super duper to avoid carbon build up

so to the point....

although the super gives the illusion of more power due to the smoothness of the engine & deeper exhaust note....

my bike is faster & runs more crisply on the regular

[Chitchats]

Fascinating , I use "super" not for the performance which i cant really notice compared with Regular but more for the fact that its a cleaner fuel and better mileage, i commute 160 k round trip a day. And carbon build , not in my bike .

[photomike666]

Many of the higher grade fuels, such as BP Ultimate use an additive the call a 'detergent', which is specifically designed to reduce carbon build up.

Many moons ago I ran back to back tests of all the major fuels, Mobile, Shell, Caltex and BP using both premium and super grades. We have 3 grades available at Aus pumps (91-standard, 95-premium and 98-super). Most sports bikes are designed to run on a min 95. I only used 95 & 98 as per the manufacturers recommendation. 3 tanks of each fuel, same commute each day. I always got more Kilometers per litre on the 98, but the price difference made it more cost effictive to use the 95. BP fuels gave the best results followed by Mobile and then Caltex. At the time shell were using Optimax, which did not work with carbs and fouled the plugs with in 1 tank. This has now been replaced by V power.

As for storage, any fuel will go off within a couple of months. It's best to run the bike dry, fill the tank with fuel but do not run the bike and then drain the fuel out when you want to ride again. Keeping the tank full prevents the internal tank surface from rusting.

HTH

[Strika]

My ZRX will ping (pre-ignite for you dummies) on 91Ron, on 95 it doesn't ping nor does it on 98. I can tell by the seat of my pants that the 91 has less go throught the rev range, but no dscernable difference between 95 or 98.

[Phil]

My ZRX will ping (pre-ignite for you dummies) on 91Ron, on 95 it doesn't ping nor does it on 98. I can tell by the seat of my pants that the 91 has less go throught the rev range, but no dscernable difference between 95 or 98.

Me too

[jefflthomas]

My ZRX will ping (pre-ignite for you dummies) on 91Ron, on 95 it doesn't ping nor does it on 98. I can tell by the seat of my pants that the 91 has less go throught the rev range, but no dscernable difference between 95 or 98.

maybe you have carbon from using Super

[tim]

For us Aussies, what do you mean by super and regular?

Leaded?
Unleaded?
Approx RON?
Ethanol?

[jefflthomas]

As for storage, any fuel will go off within a couple of months. It's best to run the bike dry, fill the tank with fuel but do not run the bike and then drain the fuel out when you want to ride again. Keeping the tank full prevents the internal tank surface from rusting.

keeping the carburetors full also prevents internal corrosion & prevents O-rings & such from drying out

actually i did drain my carbs for my first 15 years or so of owning a bike....

but for last 25 years or so i've used a top notch stabilizer & haven't had to touch a carburetor for maintenance reasons

btw...did i mention it's also a Fuel System Cleaner.. so it's like giving them a wash for 5 months a year..LOL

* Raises MON octane rating up to 10 numbers
* Improves throttle response and acceleration
* Prevents pinging and spark knock
* Stabilizes oxygenated and ethanol enriched gasoline
* Absorbs moisture in fuel system
* Preserves gasoline up to 16 months
* Eliminates gum and varnish build-up
* Catalytic converter safe
* O2 sensor safe
* Lead substitute
* Fuel injector cleaner

[jefflthomas]

For us Aussies, what do you mean by super and regular?

Leaded?
Unleaded?
Approx RON?
Ethanol?

highest octane & lowest octane at 3 grade pumps...read this>> http://en.wikipedia.org/wiki/Octane_rating

[Nelso]

I use 95 in Spring, Summer, Autumn and Winter. No storage needed over here.

[Nelso]

My ZRX will ping (pre-ignite for you dummies) on 91Ron, on 95 it doesn't ping nor does it on 98. I can tell by the seat of my pants that the 91 has less go throught the rev range, but no dscernable difference between 95 or 98.

maybe you have carbon from using Super

Nope, it pings because the compression is too high for 91Ron. Anything with a compression ratio around 10:1 or higher will not run on 91 without pre-igniting) so all sportsbikes over here come with instructions to run on premium 95 unleaded.

[jefflthomas]

Nope, it pings because the compression is too high for 91Ron. Anything with a compression ratio around 10:1 or higher will not run on 91 without pre-igniting) so all sportsbikes over here come with instructions to run on premium 95 unleaded.

well that's wierd!!!...WTF are you guys for gas?!?!..LOL

btw... a stock ZRX is 10.1 to 1

anyone got a ZRX Handbook handy???

[oldman]

Use the lowest octane you can without having it ping. Ping or predetonation is caused by the fuel igniting because of the combustion chamber tempurature exceeding the flash point of the fuel. It also can be caused by hot spots on the cyinder or head due to carbon build up or improperly finished metal surfaces. Ping means the fuel is firing on the compression stroke before it should and can cause pitted or holed pistons as well as a loss of power. The higher the compression ratio the hotter the compressed air becomes, (A fixed volume of air has so many calories of heat to give it it's measured tempurature. If you compress those calories of heat you force them closer together increasing the measured tempurature, you can see the reverse of this when you use a rattle can to paint. as you reduce the internal pressure inside the can it becomes cold). Straight ethanol will be wonderful, not for it's power producing or anti ping affects, but because if you break down you can drink it and you won't give a shit. I prefer Jim Beam but any port in a storm.

[jefflthomas]

this is a well written explanation http://cmgonline.com/content/view/3312/57/ published yesterday (with input from Kawi Canada)

[robracer]

nice article Jeff