Shell Optimax
 

Having allways used Shell Optimax petrol I watched Fifth Gear last night as they ran a test on various fuels - normal unleaded, BP ultimate, Shell Optimax etc. While it didn't have much effect on engines in a low state of tune, it did make a difference to high performance engines - an Imprezza got something like a 30 bhp gain.

I can feel the difference in my 749S if I use Optimax. Throttle response is better and the bike runs smoother.

My 748 R ran 108.2 BHP at the back wheel on Optimax.

So have you thrown down the gauntlet then Steve? The SS breathes fire now then?

I've re-named it Puff - skins will be coming of rice puddings like never before!

It's true, my old SP4S runs a helluva lot smoother with Ultimate or Optimax, quicker warming up and no coughing and hunting when cold.
Add a touch of octane booster too and wayhey!!! :burn:

The exhaust note is different too, not only do you get the deep rumble but also a sharp crack like a highly tuned two stroke note mixed in.
Sounds fanstastic. :D:D

Ains.

yep i used it on my hornet 600 to great effect smoother, just generally went better:):)

Now I dont work on the way to a shell garage is the only reason I dont get it now for the s4r:o:o

I saw the program too and I was surprised....I thought the Optimax thing was just marketing bollox, but....

The ST can keep drinking the normal stuff but I'll use Optimax in the 888 from now on

AK wont use anything else for any of his bikes.

I try to remember for mine:rolleye:

I run my (rather sporty!) car on Optimax 90+% of the time. According to the forum frequented by other owners, fuel consumption is about 10% better so it pays for itself anyway.

i think that needs independent verification, throw me the keys over .... :sing::saint:

Steve? Has it made that much difference on the SS? Do you think it really is worth changing?
If it is you might persuade me to think a bit more carefully about fuel rather than just the normal mods that cost you an arm and a leg!

I used to optimax in a Zx9r and never noticed much difference may give it another go in the ducati.

Don't they reckon it cleans the engine too?

I'm trying it in our 180,000 mile volvo at the moment and recently got 30mpg on a run. Normal is about 22mpg.

Is it just a higher octane?

Phil

[Edited on 15-11-2005 by philthy]

Once upon a time long long ago, in a not so far away land, there was an oil manufacturer called Smell.
Now this oil manufacturer made a new and wonderful oil that cleaned the engine as it slicked it's way up and down the teeney tiny oilways and crevices.
But the nasty old bits of mucky poo's weren't giving up that easily, they all ganged up together and decided they would sneak past the poor lickle ickle engines oil filter.
But the oil filter was a wise old thing (2000 miles) and was having none of it, he huffed and he puffed and he stopped them in their tracks and said "No Way wil you nasty dirty horrible particles get past me"
And so the dirt was stopped. But....the pauper pressure switch was also under pressure from this build up of naughty dirt, and so the nice man on the bike knew nothing of the commotion until it was too late.
And the Smell oil company withdrew their super-cleany-licious oils, and the nice man rode his norton into the sunset.
The End

i use it occasianally and have noticed a power increase and smoother running-- but also increased engine noise-- i believe this is because the optimax does not deposit as much carbon as "cheaper" fuels and as guest1 added the oils do clean out this carbon as well-- am i right in believing that the engine relies on this carbon build up to a certain degree?

Hard to say because I allways use Optimax, but on the odd occasion I've had to put the normal stuff in (like in the middle of Lincolnshire) it doesn't seem quite as responsive.

The big difference between a car like a Subaru WRX ((STI?)and a Ducati is that the car has a knock sensor. If the car ECU detects pinking it reduces the ignition advance and that has a significant effect on power. A Fuel that allows more ignition advance before pinking is gonna produce more power.

AFAIK a Ducati or any other bike for that matter doesn't have a knock sensor?? So the the fuel used cannot have any influence over the ignition mapping/settings.

Ray.

i believe that the WRX also has a turbo, which can vary the boost depending on the fuel (knock sensor again). Not sure of how running a higher than needed octane fuel will boost power, but i could be missing something

A Lower Octane Rated Fuel Is Better

The short answer is ... Don't use a higher fuel grade than recommended, you'll make LESS power.

Read your owner's manual and find out what Ducati says your bike's octane requirements are. In a 916 I run regular grade fuel. Ducati recommends either Plus (which is better if it doesn't ping) or Premium grade in a 998.

Unfortunately, each new generation of riders has to learn this. (So you old-timers bear with me.)

Fuel manufacturers are in business to make money and gain market share, so they've played an interesting head game with consumers, especially when they chose the name for different gasoline octane levels.

Quite understandably, many riders believe that higher octane fuels are better for their bikes (and cars) since they are labeled PREMIUM. The logic being that, since it is more expensive it must be somehow better than REGULAR. In reality, the premium label originates from the higher cost to refine it, which in turn results in a higher retail cost at the pump.

Some refiners take a different approach and label their high octane fuels SUPER so that owners will think that these fuels will make their vehicles more powerful. (I'm surprised they haven't tried to call it JUMBO to get you to think you're getting more gas per gallon.) OPTIMAX is a pretty clever name too.

As a result, according to the US Federal Trade Commission, "Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need. ... using a higher octane gasoline than your owner’s manual recommends offers ABSOLUTELY NO BENEFIT. It won’t make your vehicle perform better, go faster, get better mileage or run cleaner."

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

The stated role of the FTC is to work for the consumer to prevent fraudulent, deceptive and unfair business practices in the marketplace and to provide information to help consumers spot, stop and avoid them.

Unfortunately, consumers aren't getting the message.

The fact is, higher octane fuel has no more energy stored in it than low octane fuel. Consequently, it can't increase your engines performance. The octane rating given to fuel is defined only in accord with that fuel’s resistance to detonation - or more accurately - pre-detonation. It has nothing to do with the power it can release.

Engines need a fuel that detonates in a controlled fashion - i.e. burning fast, but not too fast. In an engine that has an increased compression ratio by design, the increased pressure and temperature in the combustion chamber will cause a too-low octane fuel to detonate prior to the piston reaching top-dead-center (TDC). This results in a ping you can hear. This misfire will create forces that oppose the rotational inertia of the crank and flywheel so performance suffers.

Occasional light knocking or pinging won’t harm your engine, and doesn’t indicate a need for higher octane. But don’t ignore severe knocking. A heavy or persistent knock can lead to engine damage.

A proper air/fuel mixture when ignited by the spark plug burns, it doesn’t explode. The burn time of an air/fuel mixture is factored into the ignition timing. That is why timing settings are specified @ BTDC (before top dead center). When the air/fuel mixture is ignited the piston is still on the way up. Because of the piston velocity and the burn time of the air/fuel mixture maximum cylinder pressure is obtained just after the piston passes TDC, giving you optimum power output.

High octane fuel has additives that increase the ignition temperature of the air/fuel mix so it can be used with the higher pressures and temperatures of high performance engines. These additives were initially tri-ethyl-lead that presented health and environment risks so many countries have outlawed their use (with some exceptions for aviation fuel). These additives are intended to actually slow/delay combustion slightly.

Most modern engines are designed with a moderate compression ratio that doesn’t need leaded fuel and will run as well or BETTER on low octane fuel. Remember, it’s easier to ignite a low octane fuel than a high octane fuel and that the higher octane fuel burns slower.

Some engines are designed with high octane fuel requirements. Forced induction (turbo-charged and super-charged) engines have higher cylinder pressures so they require higher octane gas.

Older engines having carbon deposit build-up that effectively increases the compression ratio may require a higher grade gas. Modified or stock engines with high compression ratios above 11.5:1 may need to run a plus or higher grade gas.

Advanced ignition timing results in higher cylinder pressures. If your ignition advance is set too high this will also induce pinging since you are igniting the mix even more before TDC so cylinder pressures rise more quickly as the piston is still compressing and the tendency to detonate is higher. Some automobile engines even have knock-sensor protection to retard timing for this reason.

So what’s the downside of using too high an octane fuel? Higher cost with no benefits is one. Paradoxically, another is that burning higher octane fuel in an engine designed to operate at a lower octane rating can produce carbon deposits secondary to partially unburned (slower burning) fuel. These carbon deposits can build up so as to reduce combustion chamber volume and effectively raise your compression ratio, causing you to actually need a higher octane grade.

The optimum octane rating is actually slightly lower than the manufacturer’s recommended minimum stated in the owners handbook. This is to provide a safety margin in case a particular fuel delivery or brand doesn’t quite reach it's specified octane rating or to compensate for environmental changes. The octane requirement is different depending on the weather and your location.

Modern motorcycle engine management systems adjust automatically to prevent pinging. Variables that affect pinging, such as coolant temperature, ambient air pressure and air temperature, are constantly monitored by the computer to assure best performance.

For example, in the summer when your coolant temperatures run hotter, a water jacket temperature increase of 10 degrees from 160°F to 180°F would normally increase the (R+M)/2 octane number required by 2, which is one gasoline grade higher than recommended. However, the computer has a preset fuel and ignition timing map that tells it to retard the timing to avoid pinging when the temperature is high.

It's important to note that the fuel and ignition map is based on the expectation that you are using the recommended fuel. If you are using a higher than recommended octane fuel, the computer doesn't know and will still temporarily retard the timing. So the computer cannot take advantage of a higher octane fuel unless you reprogram the fuel and ignition map on a dyno.

Pay attention to the rating system specified in the manual. For motorcycles manufactured outside the US, the owners handbook will specify the minimum fuel octane requirement as either 92 RON (US Regular), 95 RON (US Plus), or 98 RON (US Premium.)

The octane rating system is different in the US. When this system is used, 87 (R+M/2) is called Regular, 89 (R+M/2) is called Plus and 92 (R+M/2) is called Premium.

The bottom line is ... for best performance use a fuel rated as close to the manufacturer’s MINIMUM recommended rating as possible. If it pings, try a different brand or use the next higher grade.

Don't mess with Shazaam - he knows best

I remember Evo magazine testing Optimax about 4 or 5 years ago they did report better running and more mpg. If I remember correctly they ran a V8 Jaguar XJR on it and said at the time that you had to run the car on the stuff for a few thousand miles before it started to improve things. At that time I had to use super unleaded in the car I had then (Evo 6) and cant honestly say I noticed any difference!? However as the nearest Shell station was miles away it was not run exclusivley on Optimax.

Shazaam - White Papers delivered on the end of cruise missiles...... :D

Nice work.

Chr*st

That's like the 2 hour lecture a scientist neighbour gave me when I said jokingly that a Tornado flew by wire so all you had to do to bring it down was cut the wire!

:D:D:D

Shazam mate - I'll read that again tomorrow when I'm more awake:D:D:D

P.S.

My Ducati rattles and knocks that much that I've got no chance of hearing it ping:lol:

[Edited on 15-11-2005 by philthy]

"These additives were initially tri-ethyl-lead that presented health and environment risks so many countries have outlawed their use (with some exceptions for aviation fuel). These additives are intended to actually slow/delay combustion slightly."

"Most modern engines are designed with a moderate compression ratio that doesn’t need leaded fuel and will run as well or BETTER on low octane fuel. Remember, it’s easier to ignite a low octane fuel than a high octane fuel and that the higher octane fuel burns slower."

"Some engines are designed with high octane fuel requirements. Forced induction (turbo-charged and super-charged) engines have higher cylinder pressures so they require higher octane gas."


Lead was introduced into petrol not only to stop knocking but to lubricate the valve seats as well. Also note, TEL (Tetra Ethyl Lead) is a heavy metal compound with a short aerial time span. It was superceded because it was shown to have a supposed detrimental effect to childrens IQ. It was replaced by Benzene one of the most dangerous carcenogens known to man, that does not come to earth quickly and is actually absorbed through the skin. As they say in the USof A, go figure. Most probably cost in actual fact.
So when you fill your bikes up wear those plastic gloves supplied for filling diesel.

I think I'm right in stating that most Ducatis have a CR around the 10.5 to 11.5:1 ratio so would gain from a higher grade. My old bus takes 3 people to push start it in 3rd, I dunno what the comp ratio is but it's bloo*y high and it does make a difference sticking a higher octane juice in it. Enough to stay with a new R1 up the straight at Croft. A mate of mine had the old Laverda Formula Mirage 1200 triple. It would not run at all on std unleaded.

Turbocharged cars have a reduced compression ratio because they are forced induction. More like around 7:1 or so.
They can practically run on paraffin rather than the other way round. If they ran standard compression ratios they would reduce the engine to **** in seconds under load.

In short and in general the higher the compression ratio the higher the octane needed, although modern engine management has minimised knock and pinking so a higher CR can be used for the same grade of petrol than of old.

I also think I am right in saying our low grade fuel is actually higher than in the USofA; 87 for the US. Wos ours 90 something?

See this:

http://chemistry.about.com/gi/dynami...od4 %3Fsp=ink

Ains.

Eh,
I've noticed a differance,
But only in my wallet..........:puzzled:

fook.well you never no. shamz one smart dude :eureka::eureka:

Theres a Shell optimax Extreme !,available abroad,thats 100.5 octane !,its apparntley got ethanol in it,as yet,shell have no plans to bring it here !
its widely available in Australia etc !

http://www.shell.com/home/Framework?siteId=au-en&FC2=/au-en/html/iwgen/shell_for_motorists/fuels/zzz_lhn.html&FC3=/au-en/tailored/shell_for_motorists/fuels/extreme/about_extreme.html

[Edited on 20-11-2005 by Simon Reed]

doesnt seem that 'widely available '
i dont think i could live with the need to find a petrol station that sells the premium grade fuel , or are octane boosers good enough to make do with scum petrol sorry regular gasoline

Serious comment: the additives in the Australian petrol are the result of a deal between public health people and Shell to discourage petrol sniffing which is a huge problem over there.

the fact that it makes your Holden V8 go better is just a happy coincidence....

Ive got an Jap spec Subaru sti9, and it had to be re-mapped, cos it was mapped to run on 100ron fuel, which is what they have in Japan!!!

I was warned not use anything apart from optimax, for risk of detonation if driven hard. If I had no choice due to lack of a shell garage, then I could use a lower grade, but keep it below5000rpm.

I have been putting it in my 999R, and it has definatly made it smoother, as she was a bit sluggish untill she got going!!:D

Just my 2 pennies worth guys!!:cool:

I've always used optimax or BP ultimate in all my cars & bikes!! Unleaded is for lawn mowers only!!:lol:

In the US their fuel is rated as MON not RON hence the different values between UK and US fuel ratings.

I am not aware of Ducatis having knock sensors, modern cars do, especially turbo cars. These monitor for detonation which would otherwise destroy an engine. Running lots of boost on a turbo can lead to det, but using a higher octane fuel can allow a cars ignition to be advanced. 1 degree advance can provide up to an extra 10bhp, which is where the above mentioned scooby prolly got its power. It had to have some kind of fuel/ignition controller as made by Greddy or Apexi to get that kind of gain. Similarly WRC teams would run water injection systems to allow the timing to be advanced. Water cools the cylinder reducing the risk of det. The oxygen released also aids combustion, particularly if the water is mixed with ethanol, which of course gives a bit more fuel. In comparison to what can be done to a car, PC111s are very very crude.

I run Optimax and most definitely feel the bike pulling stronger