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High octane fuel in 355?

Discussion in '348/355' started by Robertb, Nov 17, 2004.

  1. Robertb

    Robertb Formula 3

    Nov 19, 2003
    1,330
    South Oxfordshire, U
    Full Name:
    Robert
    My 355's manual says that it needs 95 octane unleaded.

    There is a fuel in the UK (maybe there is a similar brand in the US) called Shell Optimax which has 98 octane (and contains various additives which 'clean' deposits off the valves/cylinders). Is there any benefit at all in using this higher octane fuel, or am I throwing money away?...

    Robert.
     
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  3. ChalStrad

    ChalStrad Formula 3

    Jan 22, 2004
    2,249
    Lausanne Switzerland
    Full Name:
    Peter Mann
    98 octane also exists in France.

    Firstly, 98 Octane was a French creation. When the supermarkets got into the fuel distribution biz, the French majors (Elf and Total at the time) decided to make a top quality product that they would not sell to the supermarkets so that if you wanted "quality" you had to go to a proper gas station. The supermarkets, however, were soon able to procure 98 from independent refiners so the marketing ploy ultimately failed...
    Yes 98 octane is a higher octane than 95 and do we french users put 98 in our Ferraris and 95 in our VWs? Yes we do.
    Does it make any difference other than to one's wallet and the feel good factor that the little red car is getting the best? No, it does not, because the engine management system is designed to calibrate itself accordingly.

    You should not use less than 95 octane and that is specified on the inside of your filler cap.

    By the way, in Italy there is only 95....
     
  4. 355flyer

    355flyer Formula Junior

    Nov 1, 2004
    338
    Gadsden, Alabama
    Full Name:
    Andy Entrekin
    What about in the USA where it is 93 Octane???
     
  5. ric355

    ric355 Guest

    Dec 21, 2003
    1,375
    It is my understanding that the Octane ratings between US and Europe are not directly compatible. So 93 USA is not the same as 93 Europe. I seem to remember reading a post on this somewhere on FChat...
     
  6. ric355

    ric355 Guest

    Dec 21, 2003
    1,375
    Oh, and I only use Optimax in my F355. I've never tried normal unleaded for any lengthy period so have no idea if it makes any real difference other than to the wallet. It's just a habit I got into from my TVR days; that engine was designed to run on 97 or better.
     
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  8. ChalStrad

    ChalStrad Formula 3

    Jan 22, 2004
    2,249
    Lausanne Switzerland
    Full Name:
    Peter Mann
    Correct
     
  9. 355flyer

    355flyer Formula Junior

    Nov 1, 2004
    338
    Gadsden, Alabama
    Full Name:
    Andy Entrekin
    then what is the conversion???
     
  10. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    The conversion is not that simple as Europe is Research method or RON and in the States is (RON+MON)/2 where MON stands for Motor method. In order to get 93 with US method, one would have to mix higher octane with 91 to gain the 93 Octane (2 parts of 100 octane with 7 parts of 91 octane will yield 93 octane).

    While I agree with ChalStrad that ECU will manage octane variations even if you violate the minimum. There are knock sensors on the engine to figure if there are detonation, which is cause of octane deficiency and will retard the timing to compensate while your HP and Torque will suffer.

    The new Ferrari manuals specify a 95 - 98 RON and yes, you can actually run some experiments to see if the added octane can change your performance level.
     
  11. 355flyer

    355flyer Formula Junior

    Nov 1, 2004
    338
    Gadsden, Alabama
    Full Name:
    Andy Entrekin
    Are you suggesting octance additives? I thought that stuff was junk. I'm a a pilot but aviation fuel is leaded. Wouldn't that burn up the cars??? I have only 93 octane in my area.
     
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  13. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    Sorry for the confusion. But there is no mention of additives in my post. I don't know how they work and don't know if they make any difference. I live in California and you can actually purchase 100 octane unleaded fuel from Union 76 station, although not all of the carry. I also understand Sonoco produces high-octane unleaded fuel for cars. I personally found that 93 octane or there about make my car run better under acceleration. I did several simple test of driving from 30 to 60 MPH in 3rd gear and measured the elapsed time with different mixes. And since there is no 93 available here I mix the 100 with 91 as mentioned before.

    Do not use leaded gas or additives in your tank, you will ruin your catalyst converters.
     
  14. cinquevalvole

    cinquevalvole Formula 3

    Feb 6, 2004
    1,151
    Germany, Bayern
    We can use Shell V-Power, 100 Oktan, in Germany. Less dirt in it.
    Good enough for Schumi - so for us :)

    forza

    cinque
     
  15. rossi

    rossi Formula Junior

    Feb 6, 2004
    480
    No engine can use the benefit of 100 octane fuel. Several tests have proven that.

    When the 355 was introduced, there was nothing higher than 95 octane in Italy, so fueling anything higher than 95 octane is useless and will only effect the thickness of your wallet.
     
  16. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,918
    Texas
    Full Name:
    Steve Magnusson
    In this discussion you need to consider that the Euro octane rating numbers are RON and the US octane numbers are AKI (e.g., 98 RON is about 93 AKI)
     
  17. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    That is not true! The use of octane in an engine will be determined by the mapping of engine i.e. timing and air/fuel ratio as well as compression ratio. Nevertheless, I am interested to see the test and examine the conditions.
     
  18. rossi

    rossi Formula Junior

    Feb 6, 2004
    480
    I think it is! It's true that the mapping of the engine adapts power/efficience according to the quality of the fuel. I didn't say it doesn't matter if you take 91, 95 or 98 fuel (in case of the 355 only 91 and 95). But currently there is no engine, that can benefit from of the extra 2 octane between 98 and 100. So the 100 octane is only an expensive marketing gag of the oil companies to earn more money. Shell engineers are even quoted "that they are amused about customers, that buy their new and expensive 100 octane V-Power fuel and really think that their engines would go faster".
    There are some tests showing exactly that result. For example a test of German motoring club adac, analysing the effect of Shell V-Power on Audi A3 2.0 FSI, BMW 316i, Porsche Boxster (all three recommended fuel 98 octane) and VW Golf 1.4 16V (recommended fuel 95 octane): nearly all results were within the measuring tolerances.


    power (kW)
    with recommended fuel:
    Audi: 109,2 - BMW: 88,0 - Porsche: 165,3 - VW: 59,7
    with Shell V-Power:
    Audi: 109,5 - BMW: 87,7 - Porsche: 167,5 - VW: 60,7
    improvement (%):
    Audi: +0,3 - BMW: -0,4 - Porsche: +1,3 - VW: +1,7

    60 - 100km/h (sec)
    with recommended fuel:
    Audi: 9,65 - BMW: 11,63 - Porsche: 8,30 - VW: 15,61
    with Shell V-Power:
    Audi: 9,61 - BWM: 11,67 - Porsche: 8,41 - VW: 15,29
    improvement (%):
    Audi: +0,4 - BMW: -0,4 - Porsche: -1,3 - VW: +2,1

    60 - 100km/h (sec) through the gears
    with recommended fuel:
    Audi: 5,99 - BMW: 6,84 - Porsche: 4,01 - VW: 10,03
    with Shell V-Power:
    Audi: 6,03 - BMW: 6,91 - Porsche: 3,99 - VW: 9,91
    improvement (%):
    Audi: -0,8 - BMW: -0,9 - Porsche: +0,5 - VW: +1,2
     
  19. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    I don't want to beat this to death but the data you show here does show the Porsche and VW improved their acceleration times, even without the remapping of the engine management.
    All engine controllers are designed to work within a set of known parameters and although owner manuals specify certain grade fuel, the factory will not take the chance of all owners following the direction. I know they will tune or map the engine somewhere in the middle where lack of adequate octane cannot harm the engine, and at the same time excess octane cannot be utilized either. It has to do with idiot proofing the cars and at the same time conforming to emissions control. There are reputable engine tuners where they just tweak these conservative mapping and can squeeze more power and torque from recommended octane and even more when octane goes up. But I do agree, excess octane does not necessarily mean higher power. There is a balance of octane and engine mapping for optimum result. I for example, have determined I get better acceleration time from 30 - 60 MPH in 3rd gear if I use 93 octane. If I go to 95 the number does not change but if I go to 91 it does. 1.2 second advantage may not be much but gives me the confidence the engine is putting out its maximum while doing the same work.
     
  20. rossi

    rossi Formula Junior

    Feb 6, 2004
    480
     
  21. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    I had said that three or four post before... hence, the blanket statement of "No engine can use the benefit of 100 octane fuel. Several tests have proven that." is not true.
     
  22. rossi

    rossi Formula Junior

    Feb 6, 2004
    480
    It is, cause so far there is NO 100 octane-engine. Perhaps that'll change in the future.
     
  23. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    Regarding rossi's comments and the fact that there is NO engine to use a 100 Octane gas I have to respond to you by reminding you of your own post where you brought the data to show the time difference of three or 4 German autos which in fact shows there is a time advantage in using the 100 RON over recommended fuel. You never show the circumstances of the experiment/test but told us that the differences recorded are within the measurement tolerance. I would say if you can measure 3.99 second, 0.5 second is not measurement error unless you show me the data with reason to show the measuring device could not measure tenth or hundredth of a second accurately then why report the times as such and the test is flawed. Please back it up.

    Also, I would like to see where you picked up the quote where Shell engineers were quoted consumers are stupid to fall for their development and paying higher prices for a non-sense gas... This is the exact quote:

    "Shell engineers are even quoted "that they are amused about customers, that buy their new and expensive 100 octane V-Power fuel and really think that their engines would go faster"."

    I don't know which country they work but if they quoted Shell engineers here in the States there would be publicity chaos for Shell and those engineers would be fired on the spot.

    Thirdly, with limited knowledge and not knowing what the tuner is going to do to your car, no one should let an engine tuner mess with his/her ecu.
     
  24. rossi

    rossi Formula Junior

    Feb 6, 2004
    480
    Within measurement tolerances I meant, that the gained improvement in that test was always below two percent (one exception: 2.1%). They recorded their data on a motor-power-testing-station as well in their standardised ADAC-car-test-routine (sorry, can't tell exactly how they do the testing).

    There are several tests over here in Germany, one was the quoted test done by the adac (German autoclub), one was from German automagazine "auto motor und sport" for example. If you browse the web, you will find several sites dealing with that issue, but most of them are in German. I tried my best to translate you the measured data.

    The quote from the Shell engineer I found in an article about the new 100 octane Shell V-Power, on Swiss Telecom "T-Online". The quote comes from an anonymous Shell-engineer, who said that in another discussion forum. The original quote goes like this:

    "Ich kann vielleicht ein wenig Licht in die V-Power Diskussion bringen, denn ich arbeite in der Shell-Raffinerie, die das V-Power Zeugs in Wesseling (Rheinland) herstellt. Wir von der Technik schmunzeln über die Kunden, die den teuren Saft kaufen und wirklich glauben, ihr Motor liefe dadurch besser. V-Power ist in der Tat nichts anderes ist als das alte "Super Plus", nur eben 12 oder 13 cent pro Liter teurer. Wir bewundern dabei die Cleverness unserer Marketingabteilung, da wegen der anderen Chemiesachen, die wir in Wesseling herstellen, etliche Blendkomponenten für Treibstoffe anfallen, die uns nicht viel kosten, die Oktanzahl des Treibstoffs aber ohne großen Aufwand auf eben diese 100 Oktan statt 98 Oktan wie minimal für Super Plus erforderlich, bringen. Dabei hatte früher das Super Plus aus Sicherheitsgründen bei uns sowieso meist eher 99 - 100 statt 98 Oktan, so ganz genau kann man das gar nicht mischen.

    Ansonsten bringt das Verfeuern von 100-Oktan Treibstoff in einem Motor, der wegen seiner konstruktiv vorgegebenen Verdichtung (die Verdichtung STEIGT NICHT bei Verwendung von 100 Oktan Benzin, sondern ist nur durch die rein mechanische Konstruktion der Motors bedingt, von Ablagerungen im Brennraum mal abgesehen, bei der X9-125 ist sie 12:1) nur 95 Oktan braucht oder weniger, GAR NICHTS - EHRLICH! Durch die Eigenarten der Blendkomponenten, mit denen unter anderem die nach DIN erforderlichen physikalischen Parameter des Treibstoffs wie Dampfdruck, Siedeverlauf, Klopfzahl usw. eingestellt werden, hat Super-Benzin gegenüber Normalbenzin tatsächlich einen etwas höheren spezifischen Energigehalt, der bewegt sich aber höchstens in der Größenordnung von 4 - 5 % ( keinesfalls 9% oder mehr) und muß auch konstruktiv von dem betreffenden Motor ausgenutzt werden (z.B. durch höhere Verdichtung oder eine spezielle Brennraumgestaltung)."

    Now I try to translate the main facts from the first paragraph:
    - he works in a Shell-refinery in Wesseling/Germany, where they produce Shell V-Power
    - then comes the quote about the amused Shell workers
    - he says V-Power is nothing else than the old "Super Plus" (98 octane), but for 12 to 13 cent more per litre
    - he is admiring the marketing departement for that clever move
    - he says producing 100 octane fuel doesn't cost much more than 98 octane, and that they can produce that new fuel effortlessly
    - he says that the old "Super Plus" already had 99 to 100 octane, because it wasn't possible to blend the fuel exactly to 98 octane, the minimum octane number that is needed for "Super Plus"

    And in the second paragraph he explains the technical background, why 100 octane has no advantage (uuhhh, difficult to translate...):
    Power of an engine depends on the compression ratio (among others). The compression ratio is a consequence of the construction of the engine. So if you don't change the construction of an engine that is based on 95 octane, the use of 100 octane will bring you no advantage, because only using fuel with higher octane won't result in a higher compression ratio.

    Hope I got it right, translating technical term is one hard thing to do...
     
  25. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    Thanks for the clarification on Shell's comment. While I can relate to marketing spins and successful product launches I also feel the quote was taken out of context and only showing a narrow point the poor engineer was trying to make. As I said before engine mapping and compression ratios determine if a 100 octane is better in power/torque and acceleration. There are engines in use today with conventional distributors and high compression pistons that do take advantage of these types of fuel. But modern engines because of their engineering restrictions (i.e. emissions, availability of fuel, and cost of development for different markets) have to compromise their mapping strategy.

    The credibility of Club's test becomes questionable if they don't provide test set up and interpret the data fairly. If they just wanted to fill some pages for the reader to read, fine! But, if they are reporting statistic they should attempt in explaining the test conditions otherwise I as a reader question their intent and why or who paid them to run these test to nullify V-power Shell.

    By the way, just as you know Shell V-Power here is marketed as detergent gas that cleans car's fuel system to maximize the efficiency of the engine. It is similar to Chevron's Techron with the same octane rating of 91 octane (RON+MON)/2.
     
  26. coolblue

    coolblue Karting

    May 6, 2004
    217
    Had a 993. Optimax made it louder and faster and it gave better mileage too. Its great stuff.
     
  27. stephens

    stephens F1 Rookie
    Lifetime Rossa

    Feb 13, 2004
    4,483
    Australia
    Full Name:
    Stephen S
    Just to add fuel to the fire, higher octane fuels are generally denser. In modern cars with adaptive ECU's (sorry Ferrari still doesn't use these), such as MB, BMW, Porsche, the car has target air fuel ratios and timing that the car will "correct" for. What this means is that the ECU will "learn" to lean out the fuel mix on a higher ovtane fuel, making the car more fuel efficient. This has nothing to do with octane, it is a function of the increased density of the fuel. You can remap an ECU to change the target values and achieve worthwhile performance gains increasing the ignition advance.

    In older cars running higher octane fuel will only make the car run richer and produce LESS power. This is true for 550/575, 355 and earlier. I don't know about the 360, so can't comment.

    This can be countered by either remapping the ECU, to lean out the mix and also add some ignition advance. or changing air intake and exhaust components for more efficient (less restrictive) ones, which will have the effect of leaning out the mixture. As an example on my 550 the car with standard filters and exhaust used to run an AFR of around 13 at lower revs, through to 12.1 at redline using Optimax. With Tubi mufflers and BMC filters, this changed to 13.5 through to 12.8 at redline. Power also increased by around 15kW at the wheels. Still not ideal, but a big improvement. I am going to replace the restrictive centre muffler, which I should get me closer to the ideal AFR's and hopefully another 10kW.
    Ideally a car should run from about 14.5 at low revs down to 13.2-13.5 at max rpm for maximum power. I am referring to WOT (wide open throttle) readings here.
    On a NA motor, any mixture richer than 13-1 loses power noticebly. Leaning out the mixture from 13.5-1 has little effect on the power, but increases the risk of detonation and engine failure.
    The AFR on a standard BMW M3/M5, Porsche starts at about 14.5 and runs down to 13.2-13.4. As such there are no performance gains to be made by changing the fuel mixtures on these cars, only by inceasing the ignition advance.

    SUMMARY
    Running anything greater than the manufacturer specified octane fuel in your Ferrari will most likely LOSE power. On OBDII equiped cars you will get increased fuel economy and smoother running.

    There are only two effective ways to properly measure the AFR's.
    1. Run a probe while driving the car. Test in either 3rd or 4th gear (pref 4th if you can). On OBDII cars, you can get units that plug into the OBDII port and take the readings from the cars own sensors.
    2. On a chassis dyno, with a lambda probe. However you need to have sufficient fan capacity to create airflow for the gearing/speed you are testing.
     
  28. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    Not sure I agree with all that "lose power with higher octane" stuff. My daily driver is a different car on 98 RON than when on 91 RON. True, it's biggest improvement is in range (I get around 10% further on a tank), but it also goes much better with easily noticable throttle response difference.

    360's LOVE higher octane.

    In testing with a Challenge car, a 7 km/h slower corner exit speed became a 4Km/h FASTER end of straight speed in the same car when switching from 98RON Shell optimax to 102 RON Elf race fuel.

    The reason for the slower corner exit speed is that the drivers were different...the amateur ended up going faster than the pro down the straight because the pro only used 98.
     

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