Which octane

[Privateer]

my bike didn't seem to run very well on 87, so I switched to 89 and it seemed smoother on throttle.  (2004 620)

/shrug  seat of pants testing of course. 

[Howie]

my bike didn't seem to run very well on 87, so I switched to 89 and it seemed smoother on throttle.  (2004 620)

/shrug  seat of pants testing of course. 

Since your bike runs a higher compression ratio than most Duc 2 valvers and there are  variance in tolerances from engine to engine you could be correct.

[Popeye the Sailor]

I heard if I put acetone in my gas I can get a lot better mileage. Anyone know about this?




(Yes I am just make the beast with two backsing with everyone).

[brimo]

I heard if I put acetone in my gas I can get a lot better mileage. Anyone know about this?


(Yes I am just make the beast with two backsing with everyone).

Yep, extra handy if your doin' your nails on the freeway, you can just dip a cotton ball in the tank and use it to wipe off any smudges.

[RUFKM]

Mostly what you said make sense.  But I personally am kind of a doubting Thomas when it comes to things that Ducati says.   They may  have designed the engine but ...

+1  They don't even know enough about the engine to list the right size spark plug for my bike in the service manual.  '07 S4RS runs great on 89.

[K3V1N]

It seems to me that getting regular over premium is only saving like 40 to 50 cents a gallon. So at the max if you fill up when the light comes on we are talking about a dollar fifty a tank. I'm sure the bikes will run 50,000 miles on low grade gas.

But you own a ducati, you already bought a bike that costs more than other bikes with the same level of performance. I feel like you should just put good gas in it and enjoy!

[Triple J]

It seems to me that getting regular over premium is only saving like 40 to 50 cents a gallon. So at the max if you fill up when the light comes on we are talking about a dollar fifty a tank. I'm sure the bikes will run 50,000 miles on low grade gas.

But you own a ducati, you already bought a bike that costs more than other bikes with the same level of performance. I feel like you should just put good gas in it and enjoy!

I agree with you on the price difference.

However, higher octane does not automatically equal better gas. It depends on the engine charateristics.

[ducatiz]

meh, i just add about half a liter of toluene to my gas tank when i fill up.  renders about 120 octane using 87 gas...  of course, my exhaust is basically The Transparent Black Death now.

[Popeye the Sailor]

But you own a ducati, you already bought a bike that costs more than other bikes with the same level of performance. I feel like you should just put good gas in it and enjoy!

Good gas is whatever the engine requires. Higher octane is in no way necessarily better.

[K3V1N]

I agree with you, but I haven't seen any dyno testing or other real results that lead me to believe that the manuals instruction to use premium fuel is wrong and that the ecu is really tuned for 87. Also that doesn't sound very Italian to me.

Like I said I think our bikes will run fine on 87 but I feel if the manual says premium it was probably tuned for that octane. I could be wrong though. I don't worry about it much I just put it the best the station has, the bike runs great and I ride it as much as a possibly can.

Ether way just get gas in the bikes and ride them

[Howie]

Good gas is whatever the engine requires. Higher octane is in no way necessarily better.

What if you want to start your own carbon factory?

I agree with you, but I haven't seen any dyno testing or other real results that lead me to believe that the manuals instruction to use premium fuel is wrong and that the ecu is really tuned for 87. Also that doesn't sound very Italian to me.

Like I said I think our bikes will run fine on 87 but I feel if the manual says premium it was probably tuned for that octane. I could be wrong though. I don't worry about it much I just put it the best the station has, the bike runs great and I ride it as much as a possibly can.

Ether way just get gas in the bikes and ride them

Bruce Meyers  did dyno runs with a superbike and found a slight horsepower loss with premium.  Your bike will also suffer carbon build up.  If it don't ping on 87, use it.  We don't use RON ratings in the US, we use AKI, which is an average of RON+MON.

[K3V1N]

The internet is amazing. I reply to a post during lunch and BAM someone replies with some information that changes my view on a topic. I did some surfing and found posts from other forums and sources with the same octane questions.

The only issue I still see would be if a bike was not tuned right and there was some type of detonation issues after switching to low octane. But from what I have read I will be trying 87 in my stock Monster.

I found this that goes along with what you are saying.

Hmm... while I can't argue with some of your arguments, I first started running 87 in my tank as per recommendations of Bruce C. Meyers, the very same man for which BCM Ducati is named... and someone who has a *wee* bit of experience with Ducatis.

They did significant testing at one point, I believe with a 996 and single injector setup that showed around 3 more peak HP while running 87 octane.

They also have recommended over the years to several customers to run 87 octane, as it tends to leave less carbon build up on the valves as it burns quicker, and cleaner. Now I am not employed by, nor do I speak for BCM or Bruce, but just trying my best to pass along some helpful info as octane use seems to be a hot topic. Also bear in mind, that European gas has octane ratings like ours, but the octane rating is calculated very differently. Generally speaking, an 87 US octane is about equivalent to a 91 european octane, which is what Ducati recommends for use in their bikes. For more on octane ratings and how they are calculated, here is a useful link: http://en.wikipedia.org/wiki/Octane_rating

Furthermore, with the addition of 10% ethanol into US gasoline, the overall combustion temperature rises by a small amount. Some of you may notice your bike consistently running a few degrees hotter than you remembered, this is why. The net effect of adding ethanol into the mix, further boosts the qualities behind which octane ratings are measured.

Granted the 996 has a 11.5:1 compression ratio while the 848 is 12:1... bust just as an example I ran my 748, 853cc kitted race bike with high comp pistons and the heads ported and valve guides worked on 87 pump gas for all 3 seasons in which I raced it.

It made 112 RWHP, once as high as 116 RWHP before the mapping was smoothed out for better driveability... again, this was on 87 pump gas.

So I'm not sure if it's "moronic" to suggest to run lower octane gas, but if you do... I suggest buying it at Shell, Mobil or similar and not at "Joe Schmoe's Gas Station."

As a rule of thumb, you want to run the lowest octane possible without detonation problems, so your results may vary.

Thanks for your reply howie!

[DarkMonster620]

I really don't know, I've filled the tank with 91 octane, here we only have 91 and 95 available; and my bike wont react as fast and it'll sputter all the way to the cleaners...
So, I only use 95 oct and from time to time a little avgas to 'clean' the valves.

[Howie]

I really don't know, I've filled the tank with 91 octane, here we only have 91 and 95 available; and my bike wont react as fast and it'll sputter all the way to the cleaners...
So, I only use 95 oct and from time to time a little avgas to 'clean' the valves.

The USA uses it's own system for measuring octane.  I assume you use RON (research octane number), the same as the Ducati manual.  We use an AKI number, which is (RON + MON)/2.
MON is Manufacturer's Octane Number, and is notably lower than RON.

Higher octane will not "clean the valves".  Additives in fuel do that.  The purpose of octane is to prevent engine knock (detonation).
                                                                                                   

[turbodude]

I run 87 in my multi with stock compression per BCM's & Bruce's recommendation.  Never had an issue.  I run high test in the monster due to the high compression pistons.  FWIW, with an air cooled engine, if you have spark knock issues you will hear it.  It's not very hard to find.  When I bought my monster it had JE high comps & I was unaware so I was running 87 and it didn't like it..