[JerZZR]

I just got a 2007 ZZR600 and I'm liking it a lot.

I'm wondering what grade of gas most of you folks re using in your bikes. I know the manual says to use unleaded gas with an antiknock rating of 90 or better (RON + MON)/2.

Around here that covers all grades, regular, mid-grade, and premium.

I'm just wondering if using premium will keep the carbs cleaner for longer or if it's just a waste of money and with these bikes. Any real difference between regular and premium as long as the engine is not knocking?

I'll try to attach a poll to this post if possible.

 

[Fryedchicken]

At the RPM our bikes are at any pre ignition is BAD! Piece of mind is worth the 20 cents more a gallon. Its not like I am filling a 30 gallon tank with it.....By the way, Welcome!

 

[undertow]

bike needs 91 or higher to run right. kawasaki knows what they are talking about

 

[cyberdos]

bike needs 91 or higher to run right. kawasaki knows what they are talking about

yes they do.

 

[outerfroggy1]

i dunno man i'd say the big sticker on the gas tank that says "use 91 octane fuel or serious engine damage could result" is a pretty big hint....

 

[Habsfan39]

It has to do with compression. How hard do you ride? The diff between 89 and 91 Octane in a bike that is ridden at light to moderate speeds while not being overloaded is negliable at best.

I ran 89 in mine but I did run a tank of the good stuff through it once in a while as a fuel system maint thing but if it's not knocking on 89 you're wasting you money if it really matters to you. If, like others have said, you can afford the extra for mid to premium then why not run it. The diff in price compared to filling a bike is only a matter of a few cents. Mine ran fine and I doubled the miles on it in a yr without any problems at all.

Habs

 

[JerZZR]

At the RPM our bikes are at any pre ignition is BAD! Piece of mind is worth the 20 cents more a gallon. Its not like I am filling a 30 gallon tank with it.....By the way, Welcome!

Yeah, good point. It's not that much extra to fill the bike with premium.

That's what I've been doing but was just wondering if there was an actual benefit or not. It is cheap insurance though.

 

[JerZZR]

It has to do with compression. How hard do you ride? The diff between 89 and 91 Octane in a bike that is ridden at light to moderate speeds while not being overloaded is negliable at best.

I ran 89 in mine but I did run a tank of the good stuff through it once in a while as a fuel system maint thing but if it's not knocking on 89 you're wasting you money if it really matters to you. If, like others have said, you can afford the extra for mid to premium then why not run it. The diff in price compared to filling a bike is only a matter of a few cents. Mine ran fine and I doubled the miles on it in a yr without any problems at all.

Habs

I'm not riding that hard at all really. I just got the bike so I'm taking it easy and getting aquainted with it before I ask it to do anything performance wise. I agree tht the difference in price makes using the premium worth it for insurance.

 

[jakesterama]

I have put almost 10 thousand miles on my bike with a jet kit, and full D&D pipe. I have ran regular most the entire time, but occasionally experimenting with other types. The only time I heard weird noises and noticed anything is when I lived in Iowa for a while and the cheapest 85.5 high ethanol mix gas was used. Octane ratings are right behind oil with the amount of hearsay that people repeat as fact, but it has a VERY simple explanation, "The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites." That's IT and that's ALL.

So to recap-
-Higher compression means you have the ability to make more power with proper tuning and proper components
-Higher compression increases the chance of knocking, so a higher octane rating fuel is needed

You DO NOT make more power with higher octane rating fuel, higher octane fuels DO NOT burn 'better' or faster, and higher octane fuels DO NOT carry more energy.

You may ask, "Well Jake, how about turbo-ed / supercharged engines?!?! They have lower compression ratios like around 8:1, and they still require high octane! HA YOU ARE WRONG" This is because the compression ratio only takes into account the cylinder (piston all the way down vs. TDC), and pumping the compressed air into the cylinder effectively increases the compression ratio by well... compressing more!

All that said, there is not a perfect "Relative Compression Ratio vs. Octane Level" because their are other factors, mainly engine internals and design. So a iron SBC with a 10:1 compression ratio may need 91-93 to run without a knock, our bikes at a 12.8:1 compression ratio can run comfortably on 87 because of their design.

For those interested, "how stuff works" actually explains it quite well, addressing the chemistry and other aspects fairly straight forward.
http://science.howstuffworks.com/gasoline.htm
http://auto.howstuffworks.com/question90.htm

Also, for those interested, check out this guy getting really angry about a speeding ticket,
http://failblog.org/2008/11/20/speeding-ticket-fail/#comments

 

[Fryedchicken]

Jake kinda missed one point. If I remember right a higher octane fuel has a slower burn so the ignition is designed with that factor. If you run a faster burning fuel you get knock due to full combustion happening to early in the piston travel. I often think about if I would even be able to hear a combustion issue if you are at wide open throttle with a helmet on. Then again if you baby it all the time you may never have an issue.

 

[ZZR_Dave]

I have always put 93 octane in my ZZR600 ever since its first fill up.

 

[jakesterama]

Jake kinda missed one point. If I remember right a higher octane fuel has a slower burn so the ignition is designed with that factor. If you run a faster burning fuel you get knock due to full combustion happening to early in the piston travel. I often think about if I would even be able to hear a combustion issue if you are at wide open throttle with a helmet on. Then again if you baby it all the time you may never have an issue.

Sorry, but that is not necessarily true. As I said before the octane rating is ONLY the measure of how much the fuel can be compressed before it auto-ignites. A 91 octane gas, for example, possesses the same anti-knock rating of a mixture of 91% octane and 9% heptane mixture. It doesn't actually mean that those are the elements in the gas you are buying, it just acts that way. Joe could make a gasoline, and Jody could make one too. Under tests they may both be rated at '91 octane', but Joe's may burn faster, or Jody's may carry more energy. The only thing that the octane rating tells you, beyond a doubt, is its anti-knock (combustion limit) of the gasoline you are purchasing. Now in empirically, you may find instances of 87 burning faster than 91, and that may be true most of the time, but that is not what the number on a pump means.

 

[Tough-Guy]

Higher octane/"grade" fuel is manufacturer recommended because of a several things incorporated into the design to make these bike perform at the level they do.

1) Naturally aspirated static compression. The higher the compression on a working fluid, the higher the temperature increase. This is known as the adiabatic efficiency. (of said working fluid, air)

2) Ignition timing. The ignition timing in a motorcycle (sportbike) engine tends to be more aggressive than say, an economy passenger car. This aggressive timing map optimizes combustion by timing the peak cylinder pressure event with the piston at or close to TDC and converting the chemical energy in the fuel to thermal energy while reducing emissions and controlling end-gas temperatures. The down side is, it brings the fuel/air charge close to the auto-ignition/detonation threshold.

The actual burn rate between the pump octane ratings varies only by a small amount of feet/second.

There are many other factors affecting performance, fuel efficiency (BMFC) that I'm not going to get into for obvious reasons, but from real-world experience, performance bikes that I have seen that have been consistently run on lower octane fuel tend to have more carbon deposits through out the induction and combustion area, run hotter, and show more signs of wear at a given service interval.

If the people that designed the bike and spent millions in R+D to produce it say use 91, then it's probably not a waste of money to use 91 in your bike.

 

[whitehendrix]

basically (correct me, T-G if i'm wrong.. lol) your octane is , in its most basic explaination, an anti-knock rating, if you will.

look at race gas.. taking note of the numbers on, lets say VP fuel. thers C12, C16, and so on.. now, this was explained to me by the big wig at VP in person, that the number "12" in C-12 denote a rough target comrpression, as does the others.. so, C-12 is ideal for 12:1 compression, C-16 is ideal for 16:1.. and so on.

many things can produce knock. fuel grade is only one of them..

 

[Tough-Guy]

basically (correct me, T-G if i'm wrong.. lol) your octane is , in its most basic explaination, an anti-knock rating, if you will.

look at race gas.. taking note of the numbers on, lets say VP fuel. thers C12, C16, and so on.. now, this was explained to me by the big wig at VP in person, that the number "12" in C-12 denote a rough target comrpression, as does the others.. so, C-12 is ideal for 12:1 compression, C-16 is ideal for 16:1.. and so on.

many things can produce knock. fuel grade is only one of them..

You are correct in that the octane rating is a measurement of the fuel's anti-detonation property (flash point). The numbers in "c-12,C-16" (to my knowledge) are specific to fuel blend, not necessarily applicability to an engine with a given compression ratio. Many factors, including but not limited to, determine an engines resistance to detonation such as combustion camber design, quash, valve configuration, bore/stroke ratio, ect.
A V-8 big block with a 13:1 comp ratio may differ greatly in combustion efficiency, BMFC, and detonation threshold, than say an inline four bike engine with a 13:1 comp ratio.
Running C-12 or C-16 will typically net different results between the two engines.

 

[whitehendrix]

thanks man.

and this is why i respect your opinion!

the C-12/C-16 stuff was told to me by a bigwig from VP Fuels, and it is half and half.. half the forumla and blend of herbs and spices, half the copmpression thing i mentioned. that was at a bike race at summit point raceway this past summer.

 

[shands]

Even though it costs an arm and a leg over here in the UK - I always opt for the high octane fuel (97 or even 99 ron in some petrol stations) for my bike. It might just be me, but they just seem *so* much more pokier with decent fuel!

As a basis for comparision, 97ron fuel over here (US equiv of Premium) is £1.06/litre at my local station. Doing a quick conversion on Google (1 US gallon being 3.785 litres, that's about £4.01 for 1 US Gallon) thats ~US$6.17 for 1 US Gallon.

As someone said on here - I'm not filling my car, so I don't mind too much paying the extra 20p/litre for decent fuel. And I know that the bike is thanking me for it!!

 

[Tough-Guy]

thanks man.

and this is why i respect your opinion!

the C-12/C-16 stuff was told to me by a bigwig from VP Fuels, and it is half and half.. half the forumla and blend of herbs and spices, half the copmpression thing i mentioned. that was at a bike race at summit point raceway this past summer.

C16 may have a higher anti-detonation threshold than C12 making it a better candidate for higher compression engines, but saying that it is designed for a specific compression ratio is irresponsible at best, and is probably the reason that guy from VP fuels is a regional rep. (or w/e) and not a chemist.