100 octane or 91?
06-14-2013, 07:26 PM
#32
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MotoGP
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the octane ratings are calculated differently in NA compared to Europe. Ours is the R+M/2 method (R = reserarch, M = mechanical). I think ratings semantics aside, the "true" octane ratings (as a resistance to detonation) are very close (ie. our 87 would be close to your 95, or whatever your "regular" is rated at).....
06-14-2013, 07:30 PM
#33
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Some years ago, someone did a dyno test on a snowmobile engine (carbureted, liquid-cooled two stroke 700cc twin) that was rated for 87 octane. Switching to 91 octane (no changes made) resulted in a 2 hp loss........ again, it is generally recommended that one use the lowest octane rating that will maintain detonation protection, and get the best performance (and cheapest operating cost).....
06-15-2013, 12:07 AM
#34
Out of my mind, back in 5
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the octane ratings are calculated differently in NA compared to Europe. Ours is the R+M/2 method (R = reserarch, M = mechanical). I think ratings semantics aside, the "true" octane ratings (as a resistance to detonation) are very close (ie. our 87 would be close to your 95, or whatever your "regular" is rated at).....
06-15-2013, 05:41 AM
#35
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Join Date: Oct 2012
Location: Ottawa Ontario
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here is another article on gas but this time as it pertains to motorcycles.
they refrence a katana for a lot of it and talk of compression ratios.
Katana is 600cc with a compression of 11.3:1 ~65HP said to be a de-tuned gsxr motor.
As most here will know
VTR is compression of 9.4:1 HP ~ 103HP
Understand Motorcycles & Fuel Octane Numbers
they refrence a katana for a lot of it and talk of compression ratios.
Katana is 600cc with a compression of 11.3:1 ~65HP said to be a de-tuned gsxr motor.
As most here will know
VTR is compression of 9.4:1 HP ~ 103HP
Understand Motorcycles & Fuel Octane Numbers
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06-16-2013, 07:16 PM
#39
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Sticker under the seat reads Gasoline 91 ron.
Reading on wikipedia it says that MON is always lower then RON, so 87 R+M/2= will always have a 91 or greater ron rating (see wiki for table).
Ethonal will not hurt your hawk!
from the owners manual (pg 36)
Petrol containting Alcohol
if you decide to use a petro containng alcohol (gasohol), be sure it's octane rating is at least as high as that recommended by Honda. There are two types of "gasohol". one containng ethanol, and the other containing methanol. Do not use petrol that contains more then 10% ethanol. Do not use petrol containing methanol (methyl or wood alcohol) that does not also contain cosolvents and corrosion inhibitors for methalon. Never use perol containing more then 5% methanol, even if it has cosalvents and corrosion inhibitors
So ya Honda says 87 (usa, canada) is what is needed!
Ps. I'm still running 91..
Reading on wikipedia it says that MON is always lower then RON, so 87 R+M/2= will always have a 91 or greater ron rating (see wiki for table).
Ethonal will not hurt your hawk!
from the owners manual (pg 36)
Petrol containting Alcohol
if you decide to use a petro containng alcohol (gasohol), be sure it's octane rating is at least as high as that recommended by Honda. There are two types of "gasohol". one containng ethanol, and the other containing methanol. Do not use petrol that contains more then 10% ethanol. Do not use petrol containing methanol (methyl or wood alcohol) that does not also contain cosolvents and corrosion inhibitors for methalon. Never use perol containing more then 5% methanol, even if it has cosalvents and corrosion inhibitors
So ya Honda says 87 (usa, canada) is what is needed!
Ps. I'm still running 91..
06-16-2013, 10:58 PM
#40
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I have a Yamaha 2stroke outboard and the carbs are really sensitive to fuel sitting in them. So I use the no ethanol fuel in them. Most of the marinas in my area have no ethanol gas and there are several local gas stations that at least have no E premium. Anyway, the outboard cautions have spread to the bikes.
07-08-2013, 03:32 PM
#41
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Superstock
Join Date: Apr 2013
Location: SF Bay Area
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I just switched from running 91 to 87 Octane and the seat of the pants dyno says that the bike is running smoother and the math says better gas mileage without a change in riding style...up until now I was a firm believer of only 91 in bikes but now I have to say 87 works better for me....Now the next change is to a OEM style filter from a K&N, but that's another thread
07-09-2013, 12:17 AM
#42
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Squid
Join Date: May 2011
Location: Haverhill, MA
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I just switched from running 91 to 87 Octane and the seat of the pants dyno says that the bike is running smoother and the math says better gas mileage without a change in riding style...up until now I was a firm believer of only 91 in bikes but now I have to say 87 works better for me....Now the next change is to a OEM style filter from a K&N, but that's another thread
......either way, I'm interested to know. Thanks.
07-09-2013, 01:08 AM
#43
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How long have you been running since you made the switch? I always heard that a motor can become "conditioned" to running a certain octane and then run like crap if it isn't getting that level. Maybe that was before the ethanol came into play, maybe I'm just a gullible ******** ......either way, I'm interested to know. Thanks.
......either way, I'm interested to know. Thanks.A fully computerised engine with FI though, has a memory, and does indeed run like crap in the exact sitiation you describe, since it's sensors and adjustability is lagging behind, and all set for higher octane...
07-09-2013, 01:51 AM
#44
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Well... Apples and oranges... A carb'ed engine has no memory what-so-ever...
A fully computerised engine with FI though, has a memory, and does indeed run like crap in the exact sitiation you describe, since it's sensors and adjustability is lagging behind, and all set for higher octane...
A fully computerised engine with FI though, has a memory, and does indeed run like crap in the exact sitiation you describe, since it's sensors and adjustability is lagging behind, and all set for higher octane...
.
07-09-2013, 05:59 AM
#46
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SuperBike
Join Date: Sep 2010
Location: Bisbee, AZ
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Some years ago, someone did a dyno test on a snowmobile engine (carbureted, liquid-cooled two stroke 700cc twin) that was rated for 87 octane. Switching to 91 octane (no changes made) resulted in a 2 hp loss........ again, it is generally recommended that one use the lowest octane rating that will maintain detonation protection, and get the best performance (and cheapest operating cost).....
Now move along, nothing else to see here.
07-09-2013, 09:37 AM
#47
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Superstock
Join Date: Apr 2013
Location: SF Bay Area
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How long have you been running since you made the switch? I always heard that a motor can become "conditioned" to running a certain octane and then run like crap if it isn't getting that level. Maybe that was before the ethanol came into play, maybe I'm just a gullible ******** ......either way, I'm interested to know. Thanks.
......either way, I'm interested to know. Thanks.
07-09-2013, 10:32 AM
#48
Out of my mind, back in 5
MotoGP
Join Date: Nov 2006
Location: Skurup, Sweden
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Some people should probably read the ENTIRE THREAD before posting... Makes them look less ignorant...
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