Ducati Monster Forum

What do people think of this article?  Does Ducati's ECU compensate for knocking? I didn't realize that going up in octane increased performance!  Discuss.

***************************************
http://www.nytimes.com/2008/08/03/automobiles/03OCTANE.html?pagewanted=print

Premium Required? Not Necessarily
By DEXTER FORD
AT today’s prices, it’s understandable that drivers accustomed to filling their gas tanks with premium would be looking for ways to ease the financial pain.

Some relief may be as close as their next fill-up. Switching from premium-grade to regular unleaded can save several dollars on each tankful, given an average price difference of about 30 cents a gallon, according to end-of-July figures compiled by AAA.

While using gasoline that carried a lower octane rating than the engine required was once a sure path to disaster, that is no longer the case. Nearly all automobiles sold in the United States since the 1990s will happily run on regular-grade 87-octane gasoline without causing engine damage, a benefit of the electronic controls that now manage all engine functions.

The octane number posted on the pump is a measure of a gasoline blend’s resistance to a condition called knocking. The knocking sound â€" a rattling noise made by an engine under load, familiar to drivers of older cars â€" is a result of out-of-control combustion, the mixture of air and fuel burning erratically. The explosion rings the metal of the engine block like a bell.

The higher the octane rating, the more temperature and pressure the gasoline can withstand before it ignites on its own, rather than when it is set off by the spark plug. An engine that calls for premium gas typically has a higher compression ratio â€" it squeezes the air and fuel mixture to higher pressures â€" which can improve both fuel economy and power output. But such an engine requires the higher octane rating to run properly.

Before the switch to fuel injection and computerized controls, engines were subject to damage from prolonged knocking. But today’s engine management systems incorporate electronic knock sensors, which detect the condition and adjust the ignition to stop the problem. As a result, it is almost impossible to hurt a current engine by using 87-octane fuel, industry experts say.

“Modern engines prevent the damage from happening before it starts,” said Patrick Kelly, a fuels analyst with the American Petroleum Institute. “It wouldn’t impact fuel economy. And it wouldn’t impact the emissions. What it would impact is the performance.”

Of course, owners who do not heed the automakers’ recommendations may face consequences â€" the potential voiding of warranties, for instance. But for the most part, manufacturers’ fuel recommendations include some wiggle room.

Porsche, for example, acknowledges that any of its modern production cars can be run on regular fuel without the risk of damage.

A spokesman for Porsche North America, Tony Fouladpour, added a caveat. “If you want the car to perform at its maximum capability, the best choice would not be 87,” he said. “But we do not forbid it.”

Specifying premium fuel lets a car manufacturer squeeze out more horsepower. BMW, for example, recommends that all the cars it sells in the United States use premium fuel, but they will run on regular.

“There generally isn’t any harm done to the engine by using lower-octane fuel,” said a BMW spokesman, Thomas Plucinsky. “Because our engines do have very good forms of knock sensing and are able to deal with lower-octane fuels, you will not have any drivability issues. You will, however, lose some of the performance.”

How much of a loss? Some indication can be found in the peak horsepower numbers Hyundai recently released for its new Genesis sedan. On premium, the 4.6-liter V-8 engine is rated at 375 horsepower. On 87-octane regular, it is 368.

That seven-horsepower difference â€" less than 2 percent â€" seems a small penalty for saving 30 cents a gallon, especially when you can regain that performance simply by filling up with premium.

Does using lower-octane fuel reduce mileage or increase emissions, as some drivers believe? Not according to the Environmental Protection Agency. “E.P.A. fuels engineers say that there isn’t a meaningful difference between regular and premium gasoline,” said Dale Kemery, a spokesman for the agency.

Still, the warning from some automakers can give an owner pause at the pump. The manual for the Smart Fortwo repeats the warning issued for other vehicles sold by Mercedes-Benz: “To maintain the engine’s durability and performance, premium unleaded gasoline must be used.”

But even those stern words may have some room for interpretation. Dave Schembri, president of Smart USA, told John Schwartz, a reporter who was writing for this section’s blog about his experiences in buying a Smart, that he should not worry.

“You could use regular gas â€" there’s no damage to the car,” Mr. Schembri said.

If an engine is designed for a higher octane fuel. then thats what you need to use for maximum power. Its just a matter of more compression. If you run a engine thats high comp and put 87, it will predet and you loose out on maximum performance. however our Monsters (2v atleast) are designed to run on 87. so you dont get power out of 93 unless you drop up the compression. You lose alot of mpgs though.

Of course we've beat this horse to death already, but.  Ducati does not have any form of active knock sensor or control that I am aware of. That being said, there is more to it than active control where octane is concerned. The cylinder head design of most 4V heads will tolerate a relatively lower octane than back in the "good ole" days.  I remember the first 4v designs referred to as "quick burn".

The BIG deal to me is what the manufacturer who designed the engine recommends and this taken into consideration with the octane rating scheme one is using as reference. 

For our bikes 89 R+M/2 is equal to about 94 (5 points higher) than the Euro RON number of 95 that Ducati recommends and is certainty adequate for modern Ducati's. Argument abounds that 87 is adequate. And remember our bikes don't vary timing to "take advantage" of higher octane anyway.

Having said all this, I use 93 octane anyway. ;D

LA

quote from article

The higher the octane rating, the more temperature and pressure the gasoline can withstand before it ignites on its own, rather than when it is set off by the spark plug. An engine that calls for premium gas typically has a higher compression ratio â€" it squeezes the air and fuel mixture to higher pressures â€" which can improve both fuel economy and power output. But such an engine requires the higher octane rating to run properly.

I find this interesting.  In the same article it states
“It wouldn’t impact fuel economy. And it wouldn’t impact the emissions. What it would impact is the performance.”

Which sort of begs the question, Does it not got better fuel economy because it is performing better? Because it is "stronger"

i think that performance = power, or faster, for the sake of that article
that being said, faster (usually) = lower mileage

Quote from: herm on August 04, 2008, 10:21:09 AM
i think that performance = power, or faster, for the sake of that article
that being said, faster (usually) = lower mileage

My line of thought was...
Take an SUV.  Put one with a 4 cyl engine and one with v8.  Have both cruise at 60 mph.  What gets the better gas mileage? 

Something like the bmw vs prius test.  The bmw got better gas millage than the prius. 

If you graphed it out, at one point it would cross each others path. The question is what speed is that? (assuming same driving conditions)

And 93 vs 87 no mpg difference? Kiss ass. I got a huge jump in MPG from 93 to 87.

Oh dear. This again. I've had significant trouble trying to explain the science of combustibles, in this case gasoline to my friends and particularly my girlfriends dad, who is convinced that you should always run your car/ bike on the highest octane available. Reading up on this I've discovered convincing arguments both ways. I've discussed it so heavily with my friends that I have become unsure if I even understand it any more. Somebody correct me if I'm wrong but...

It's my understanding that you can use whatever you want, you're not going to damage anything (although some people are convinced that lower octane gas is 'lower quality' and thus dirty.. blah blah leaves engine deposits.. you get the picture) however, you should get the best results i.e; Performance+MPG by using the recommended octane  due to the fact that the engine is set a certain way and by using the octane concentration the parameters of the engine were designed around you maximize its ability to produce a balance of performance and mpg based on the manufacturers reckoning.

So, herein lies the question: What the make the beast with two backs octane should we be using, is it affected by mods like air box, exhaust etc.. probably 90% of monsters are modded in some way performance wise. I'd like to know if anyone could explain the scientific reason why I should be using a particular grade.. I use 93 right now but I certainly won't any more if someone can tell me I'm going to get a better balance of power+mpg with a lower octane... Somebody enlighten me/ us! I can't take it any more haha.

i take the whole recommended fuel suggestion from the manufacture like i take the recommended oil manufactuer in the manual. my 94 says i should only use agip because at the time, thats who sponsored ducati, but i use mobil 1.  is my bike going to blow up because im not using agip lubricants, heck no. i change the oil regularly, and maintain my bike.  ive grown tired trying to explain why its dumb to use premium for around town driving, your never using your car to its true maximum potential anyways.   bottom line, use the least octane your engine can handle, any more and your just throwing money away. but i guess all that marketing that the gas companies do works, cuz there are tons of people that put premium in their lawnmowers for maximum power, cuz everyone knows that lifes a racetrack, and 2nd is the first loser. GOGOGOGO !!!!

stop reading and try it. if your really scared, try half a tank  of 93 and 91, then jus 91. and go from there.  if someone starts knocking on your front door, pm me and ill give ya my address so you can come lynch me for hurting your monster.

Quote from: OwnyTony on August 04, 2008, 10:11:51 AM
I find this interesting.  In the same article it states
“It wouldn’t impact fuel economy. And it wouldn’t impact the emissions. What it would impact is the performance.”
Which sort of begs the question, Does it not got better fuel economy because it is performing better? Because it is "stronger"

Interesting fact:  My 1997 Acura 3.2TL car is designed to run high octane fuel and high octane fuel is recommended on the sticker inside the fuel door and in the owner's manual.  I run the same highway route to and from work each day and I experimented with different fuels.  Here's what I found (for something with premium recommended)

87 octane fuel ran just fine, but turned in the poorest fuel economy.  Subjective feel was no different.
89 octane fuel ran just fine, but turned in middle fuel economy.  Subjective feel was no different. 
92 octane fuel ran just fine, felt the same as the other two, but turned in the best fuel economy.

It is cheaper to run the higher octane because of the fuel mileage increase.  Even though the premium fuel, in a car designed for premium fuel, costs more per gallon, it returns more mileage and is overall cheaper to run.  Odd, but true. 

These tests were done with many tanks of fuel over a long period of time and averaged.  It's pretty accurate. 

NOTE!!! 
This is with a knock sensor equipped engine that will adapt to the lower octane.  Ducati does not do this.

The end conclusion is this:  You use what the engine was designed for.  Using low octane in my car doesn't work well.  Using low octane in my 96 M900 works just fine.  There is no "easy" answer. 

Quote from: He Man on August 04, 2008, 03:59:32 PM
If you graphed it out, at one point it would cross each others path. The question is what speed is that? (assuming same driving conditions)

And 93 vs 87 no mpg difference? Kiss ass. I got a huge jump in MPG from 93 to 87.

You are right about the graphing, at some point, they will intersect.  I was just nit picking.  Given that your engine is a high performance engine optimized for the higher octane, With the same volume and density of gas, you are squeezing out a tad bit more power (combustion at higher compression) with the higher octane which would translate in a positive effect on mpg.  Is this slightly greater mpg economical for the extra 20-30 cents you pay?  we need graphs for that.

Well. When i get my bike back with my new valve guides (yay!) i will do a semi scientific test on 87 octane, 89 octane and 93 octane, with 10% ethanol mix.

heres what i think of the setup.

I am going to make a marker on my fuel tank so i know where to stop filling up each time.

I go thourgh about 1.5 tanks a week. sometiems 1 depending on which. so this test will take a bit. I will do 3 runs of each fuel, with consistent riding conditions. 80% city. 20% highway. 80% city is a very very aggressive riding, on and off on the throttle every 3 seconds and lots of gasing to catch lights. I ride at the same time so traffic is very consistent since theres alwyas a dumbass blocking traffic everyday. lol

I will fill up every single time my bike reaches 90miles (because i dont think i can hit 100 without the light turning on lol) and graph the data. with each run, and a final graph with averages.

But ill just say right now. I use to run 93 octane in my S2R1k riding the same way i do now, (probably much harder now since im getting back into the rhythm) i was getting 70miles per tank before the light came on, and i filled up 2.7gallons avg. after the ~4000 miles (started the bike with 4444 miles, now over ~8700) when i fill up at 80miles on the odo, i only fill up 2.1 gallons. and this is nasty inner city riding with occasional wheelies and i ALLWAYS blip my throttle at lights, why? mostly casue i like to look like a bad ass.  [moto]  ;D and to remind everyone im around them.

Im hoping my valve guides will bump my MPG up to 45city. I havent trie 93 since my bike broke in. and even with 87 octane, i still get some pinging in my udder when i shut the bike of. which means theres still detonation going on from unburnt fuel. So i think 93 octane will kill my mpg.

Fuel mileage and performance aside...

high octane fuel will cause carbon build up in a stock Ducati motor.

I've used 87 since I got the bike, 96 M900, and have had no issues.

For those who believe "premium fuel" is cleaner and has better detergent/additive packages, all we know, unless we get a lab to analyze the product, is the fuel meets minimum government standards.  An exception would be fuel that meets the Top Tier gasoline standard.       http://www.toptiergas.com (http://www.toptiergas.com)     Notice that Top Tier makes no mention of premium verses regular.   Any other claims made by the manufacturers are just that, claims that may be true or may be just advertising hype.

Ducpainter's claim that high octane fuel will cause carbon build up in engines that do not require premium is certainly true when talking about "clean" (ethanol laced) fuel that most of us are forced to use and probably true in general.  Some people have also found a reduction of power output in dyno testing with use of premium fuel when not needed.  Fact of the matter is ethanol does not atomize well.

Fuel economy needs to be averaged over at least a few tanks of fuel under similar operating conditions.  There is too much error tank to tank.  A couple of extra cold starts and a little extra idling time on a single tank will make a notable difference.

The manuals for my GTI and Passat both say premium fuel.  I looked in a European manual and it stated 91-95 RON.  91 RON is well below our 91-93 AKI premium.  Well, early on both cars were fed middle grade and ran better accompanied by better fuel economy (the Passat has a trip computer that logs long term and single trip economy).
I an now running 87 and the cars are running even better.  Just to make sure, I will, when my buddy is available, put the VAG tool on the GTI to check knock sensor activity.

Quote from: Butcher on August 05, 2008, 09:01:40 AM
NOTE!!! 
This is with a knock sensor equipped engine that will adapt to the lower octane.  Ducati does not do this.

Not even on the later FI bikes?  AFAIK, late model BMWs have knock sensors.  Or maybe everyone that pays for a BMW assumes they have a knock sensor.   ;D

Quote
The end conclusion is this:  You use what the engine was designed for.  Using low octane in my car doesn't work well.  Using low octane in my 96 M900 works just fine.  There is no "easy" answer. 

I've had the same experience with 87 in my '99 ML 320.  runs fine, gets worse gas mileage.  Although if I keep my foot out of it, I can regularly (no pun intended) get 22/30 mpg with 92. (highest available here without driving across town for $6/gal 94)

Quote from: He Man on August 05, 2008, 05:31:22 PM
and even with 87 octane, i still get some pinging in my udder when i shut the bike of.

This pinging has nothing to do with detonation of fuel. It has to do with the uneven cooling of metal.

I have tried the three different fuels in my S2R1K. I found that the bike runs best and backfires the least with 89, so that's what I run...