[dark620]

Hey , just read all the fuss about the fuel octane ratings, pretty juicy stuff ;D My question is In my owners manual it says and I quote " 95 fuel octane rating ( at least)". What is this RON rating that was frequently mentioned? my manual doesn't say anything about RON . that would have to lead me to beleive they are refering to regular US standards right? I purchased a bike built for north america, so do they consider this when they print the owners manual? And I promise I won't tie on any boxing gloves. ;D

 

[test-reg]

i'm going to leave out alot of details. there are 2 rating systems, MON (manufacturers octane number) and RON (research octane number). the test sequence and engine are slightly different. for some bizzare reason, in the U.S., we use the AKI (anti knock index). this is RON + MON / 2. that is what you see on the pumps. most of the world uses RON, which is what is in your Duc manual. if you do a search on this board, you will find most people are using 87AKI with no pinging problems. you will also get some excellent info on octane.

 

[CRASH!]

Here we go again....

RON is "Research Octane Number"

MON is "Motor Octane Number"

PON is "Pump Octane Number" = (RON+MON)/2

PON is what you'll always see on US pumps.

RON is often spec'ed in Europe.

MON is always less than RON (PON is obviously in between).

RON is the original measurement of "octane" i.e. the resistance of a fuel to pre-ignition, or "knock"

It is measured on a "knock engine" which features variable compression ratio. The ratio is increased until knock is sensed and that compression ratio is normalized to that which will cause pure iso-octane to preignite. Iso-octane is defined to have an "octane rating" of 100.

RON is measured with a "cold" air charge. I put cold in quotes because I don't know what that temperature is.

A cold charge suppresses knock. Some years later, the industry decided that the test didn't accurately reflect knock tendencies because in a real motor, the air intake was not always cool. The MON test uses a heated air charge intended to more closely replicate real world conditions. Any given fuel will therefore knock at a lower compression ratio in the MON test than in the RON test.

Now fuel companies faced "octane" numbers lower than customers were accusumed to and it was a marketing problem. The compromise was the average of MON and RON, or PON that we all now see at the pump.

Bottom line, your Monster works best with fuel with a PON of 87. The manual specifies a RON value. Your stock engine WILL NOT knock with 87 PON. Your plugs will likely experience chronic fouling if you use higher octane fuel.

 

[test-reg]

oops! motor is correct :-[

 

[dark620]

thank you, but I got all that info from the other post. I guess my question is : if you look in say a automobile owners manual it specifically states the R+M or PON value and most say 87. the ducati owners manual doesn't specify the octane rating system that should be applied to the figure of 95 . You are assuming that they are referring to RON considering the bike is italian . I guess that is where all the mix up is invilved, the fact that the owners manual does not spell out the particular rating that they are using. thanks for the recap. I too put the higher octane in just because of the advise from the shop where I purchased my bike and I never bother to consider the compression ratio . I just figured being air cooled and such that the high temps and 10.7 :1 compression might need a little increase in octane.

 

[RC51Mike]

You can assume it to be 95 RON and not MON or PON in the manual because at least in the US, you won't normally find a 95 pump octane at a gas station. 93 is usually the highest you'll see and 94 for Sunoco. R+M/2 has been used for a long time here.

 

[Gman86]

Yeah, but I get more HP with 100 octane! ;D Sorry, just kidding! Ignore! Ignore! [smiley=laugh.gif] [smiley=laugh.gif] [smiley=laugh.gif]

 

[AlexB]

I found this using google.. interesting rundown on MON vs. RON and PON...

http://www.btinternet.com/~madmole/Reference/RONMONPON.html

 

[AlexB]

and yet another...

http://www.grapeaperacing.com/GrapeApeRacing/tech/fueloctane.cfm

 

[Speeddog]

Yeah, but I get more HP with 100 octane! ;D Sorry, just kidding! Ignore! Ignore! [smiley=laugh.gif] [smiley=laugh.gif] [smiley=laugh.gif]

LOL, it's been a while since we had an octane slugfest. I guess we've just gotta poke that sleeping dog every now and then. ;D

The grapeaperacing.com info is a little off on some of it.

My manual says "95 - 98 RON" for fuel.

 

[Brutus]

How about MORON octane?
that's the most commonly used here right...?

blah.

 

[niuginisbk]

I was told by an aircraft engineer that RON has nothing to do with Street Bikes or Street Cars, it's only got to do with the Aircraft industry & has something to do with the High loads experienced during take off.

100/130 avgas is 100-102 Octane Guaranteed & 130 RON. I say forget about the ron!

I started one of these "Octane Issue" threads about a montha ago, & the end result is that I now run 50/50 91 Octane Unleaded Pump Gas & 100/130 Leaded Avgas, giving me "so the experts say" about 96 Octane. My Bike Loves it & has never run sooo Good!!

PS: The only reason I had to blend Avgas is because a higher Octane pump gas is not avail in the country where i live.

 

[Brutus]

ok my bike runs better with 91 than 87, period.

now the ducati ducati does say 95 at least, period.

I repeat "...AT LEAST..."

ok now some guys here know better than anyone else on the planet, and know better than engineers at Ducati.

Geez...

 

[MarkV]

the following link is probably the most complete explanation i've seen online for gasoline.

http://www.faqs.org/faqs/autos/gasoline-faq/part1/

brutus the 95 octane requirement in your manual coincides with the 95-98 RON specified by your manual. as stated previously(RON+MON)/2 is the formula for calculating octane in the us at the pump.

if pump 91 octane makes your bike run better than pump 87 octane fuel then your motorcycle engine is either modified for higher compression ratios or is seriously out of tune. period.

if you wish to discuss facts fine but don't befuddle the issue with misinformation or opinions that cannot be reinforced with data.

 

[MostroRodento]

MarkV truly you have become the "Octane Evangelist" for this website <laughing>....no sinner will go un-redeemed

"One man alone....facing the impossible odds against countless Oil Company Marketing Departments"

 

[MarkV]

gotta do something to keep myself busy when it's raining... ;D

i hold off on the thread until i read something unreasonable. in this case it was the extreme number of periods, capital letters, bad information, and the slight againt engineers that don't work for ducati. i tried to be polite in the past but after "the incident" i just wade in with both guns blazing so there's no wiggle room. ;D i guess i missed out on the soft gloves at the assembly line...

 

[Medusa]

Excuse my ignorance, but the first site that was linked had a chart comparing RON/MON/PON numbers, and one line (the third) reads as 95 RON = 87 MON = 91 PON. So everyone seems to be saying that the manual is the RON value, and that US pumps read the PON value. So wouldn't that be 91 from a US pump? But people are saying that 87 octane is best (PON I'm assumming since that is the pump number) and are apparently contradicting the ducati recommendation?

I understand the first issue with the rating system, but if 87 pump rating is indeed best, then we are also disagreeing with the ducati recommendation to begin with.

 

[MarkV]

that chart is an approximation chart... only purpose is to show the various pump grades as a result of ron and mon numbers used to generat a hypothetical pon number... it does not state that 95 RON = 87 MON = 91 PON

right above the chart it states....
"Below is an approximate comparison chart, these numbers can vary by as much as 2 grades"

check out the third link to understand how the ron and mon numbers are determined.

 

[Medusa]

Doh! I stand corrected.

And thanks, BTW, to everyone for a very enlightening discussion.

 

[dark620]

Hey, with all the confusion about what Ducati wants in there motorcycles I went to the source. The big issue is translating there 95 rating into a useful US octane rating and this is what they replied to me. Hi Jason,

Thanks for taking the time to contact Ducati. As far as your fuel goes, using the premium fuel (highest octane rating available) at gas stations will do just fine. Whether that be 91, 92, or 93 octane, any of the 90's will peform just fine. Just do your best to avoid the 80's level octanes.

Sincerely,

Ducati North America, Inc.
Customer Service
PH: 408-253-0499
FX: 408-253-4099
www.ducatiusa.com