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I have almost 500 miles on my bike and so far all I have put in the bike is shell v-power (93 octane). This is my first new bike and for some reason I have it in my head that i'm only going to use the most expensive gas I can find. I guess I have bought into shell's marketing on their vpower gas. I even got a shell decal to put on the swingarms of the bike :)

Anyway, I am wondering if this is overkill as the $0.24 or so cents a gallon premium over regular shell gas will add up over the life of this bike. I still intend to keep using only shell gas in this bike, but I may be tempted to go to regular grade... but.....

I have a corolla xrs with the 2zzge engine out of the celica gts. It has a 11.5 compression ratio and it definitely calls for 91+ octane gas. The z750s has a compression ratio of 11.3. I've heard that anything over 10.5 really needs more than regular grade gas to ensure no knocking. The manual only calls for 91 RON gas which equals our 87 octane gas here in the united states.

Why would my car require premium and my bike not? Now the car has all kinds of fancy variable valve timing and variable valve lift (that is the awesome aspect of the engine, hitting lift at 6500 rpm is awesome, but that is a whole other story). The bike doesn't have this stuff, and from what I can tell it doesn't have a knock sensor, there is no mention of one in the service manual. So the bike couldn't even retard timing if it needed to on regular gas like a car can do. Is the ignition timing/advance mild on bikes compared to cars? What do people here use in their z1000 or z750s generally?
 

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Usually put in 87. But I don't even know what is indicated in the owner's manual actually...
 

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Would running a higher Octane hurt the motor? Most of what I have read on these forums seems to indicate that most ppl use 87 over 93.
 

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I'd like to know the same thing. I'm not gonna waste my money on the good stuff if the bike doesn't need it. Now my 86 VFR runs like crap with 87 in it. Runs okay with 89 but with the good stuff it runs great.
 

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I mentioned on another thread that when I bought my Z750S they filled the tank for me at the dealership. I asked the shop guy what octane he was putting in, and he said "91, that's what they put in everything" -- he went on to tell me that I should always use the highest octane I can find.

That said, I used to have an SV650 and on the SVRider Forum there was a long discussion about octane (sounds like a joke, but I believe amongst the participants were an engineer, a mechanic who races, and a commercial pilot). They went on for quite some time about how using a higher octane than is needed or recommended can actually cause you to loose power, because higher octanes retard ignition... or something like that, I don't remember the details. All I know is that on my SV, I switched from 91 to 87 and never noticed the difference.

To piece together the other little experiences I've had; before I drove cross country in my Honda Element, I asked the service manager what I should do to prepare for the trip, since the car was going to be loaded to it's capacity. He said to put a few extra pounds in the tires, and *just for this trip* use premium gas. He was very explicit that afterwards, I should go back to regular.

With my Z750 I road the first 1000 miles with 91 (following the dealers advice), but on the last tank I switched to 87. I don't ride it that hard, I don't ride with a passenger, and I live close to sea level (I think altitude can be a factor in pinging). My only concern is that the manual says to switch to a higher octane if you hear pinging, and I doubt with earplugs and a helmet I'll be able to hear pinging.
 

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MotoYoda said:
how using a higher octane than is needed or recommended can actually cause you to loose power, because higher octanes retard ignition
MY -

I've heard and read that also. So I've been using Chevron Mid grade in my Z750 - runs great, so...........guess I'll just continue to go that route.

BTW, MotoYoda - do you EVER check your PM box?????

Miki
:silly: :silly: :silly:
 

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Originally posted by Mikimoto BTW, MotoYoda - do you EVER check your PM box?????
D'oh!! Sorry... usually they email me when I get a PM... didn't get one this time.
 

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To be honest I have never used anything higher than 'normal'/regular octane. HEre in France it is 95 octane. And so far I have had no problems whatsoever. I have noticed that during a thrashing session in the swiss alps with regular octane, my mileage/litre actually increased!! I got more out of a tank of fuel while thrashing it, than when i took it easy!? And this was not a first time either! The year before last, I went to the swiss alps on the ZR7 instead, and the same thing happened!?<this might be destined for another thread though, but i thought i will mention it anyway>
 

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Nuclear Pumpkin said:
To be honest I have never used anything higher than 'normal'/regular octane. HEre in France it is 95 octane. And so far I have had no problems whatsoever. I have noticed that during a thrashing session in the swiss alps with regular octane, my mileage/litre actually increased!! I got more out of a tank of fuel while thrashing it, than when i took it easy!? And this was not a first time either! The year before last, I went to the swiss alps on the ZR7 instead, and the same thing happened!?<this might be destined for another thread though, but i thought i will mention it anyway>
That 95 octane isn't the same as 95 would be here in the United States. Most likely that is the research octane RON number instead of the RON plus motor octane number we have here. Though it is higher than our low grade gas because our 87 r+m/2 is only about 91 RON.
 

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Check your owners manual to determine the recommended octane rating. There are two truths known to actual SCIENCE on what fuel to use:

1. The lone function of the octane inhancers in a higher octane fuel is to resist knock (detonation) in those engines that are prone to knock by reason of design or condition. Premium gas has no more potential energy than does regular gas. If your vehicle is not knocking excessively, use the fuel the manufacturer recommends. Using premium gas will NOT make more horsepower than will regular.

2. Quality 87 octane gas has enough detergent to keep the engine clean. The gasoline companies have been ordered to stop intimating that you abuse your engine if you use regular gas. Any extra/different detergent added to big-name premium gasolines is insignificant - the "more or different" detergent changes are simply for marketing purposes.

Many mechanics and other auto/moto professionals are misinformed on these points. They only repeat what they were told by others who were told...and so on...and so on...
 

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I have almost 500 miles on my bike and so far all I have put in the bike is shell v-power (93 octane). This is my first new bike and for some reason I have it in my head that i'm only going to use the most expensive gas I can find. I guess I have bought into shell's marketing on their vpower gas. I even got a shell decal to put on the swingarms of the bike :)

Anyway, I am wondering if this is overkill as the $0.24 or so cents a gallon premium over regular shell gas will add up over the life of this bike. I still intend to keep using only shell gas in this bike, but I may be tempted to go to regular grade... but.....

I have a corolla xrs with the 2zzge engine out of the celica gts. It has a 11.5 compression ratio and it definitely calls for 91+ octane gas. The z750s has a compression ratio of 11.3. I've heard that anything over 10.5 really needs more than regular grade gas to ensure no knocking. The manual only calls for 91 RON gas which equals our 87 octane gas here in the united states.

Why would my car require premium and my bike not? Now the car has all kinds of fancy variable valve timing and variable valve lift (that is the awesome aspect of the engine, hitting lift at 6500 rpm is awesome, but that is a whole other story). The bike doesn't have this stuff, and from what I can tell it doesn't have a knock sensor, there is no mention of one in the service manual. So the bike couldn't even retard timing if it needed to on regular gas like a car can do. Is the ignition timing/advance mild on bikes compared to cars? What do people here use in their z1000 or z750s generally?
The owners manual for the 2006 Kawa z750s states minimum r+m/2 of 87 (regular). I know this is an old post. However, the info would benefit of those who bought an old bike with a lost manual and want to save time (e.g. like myself). Especially, Kawa only allows you to view the manuals online and doesn't allow downloads... not very convenient if you just need to do a quick lookup before getting fuel.
 
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