Saturday, October 28, 2006 - 01:36 pm, by: Carl Johnson(Carlos)
My car is tuned to run on Optimax, have used the Premium fuels from Caltrx & PB......& Seven Eleven couldn't notice any differance at all. All seemed to give about the same mileage same power. Filled up with the new V Power 2 days ago (was 31' in the middle of the day so no nice cool air) & immediately noticed more power in mid to high range (about 3800RPM & above)
Anyone else tried this fuel? Any one else noticed any improvement?
Saturday, October 28, 2006 - 09:17 pm, by: Dominic Kelly(Drk_awd)
David Vaughan wrote on Saturday, October 28, 2006 - 02:36 pm:
Why does it confirm that? Has anyone tried a dyno rather than hearsay or their own opinion to compare 98-octane fuels?
A dyno is certainly useful for comparing maximum power capabilities of each of the fuels but often when you're driving it's the part throttle response and smoothness that are noticeably different. That sort of thing is hard to quantify on a dyno so the old "seat of the pants" dyno is what we are left with. One of those hub dynos that are very sensitive would be useful for this sort of thing.
Having said that you really have to wait for more than one tank to make any conclusion. Sometimes you can feel a difference week to week even when sticking to the same fuel.
So, Dominic and Greg, are you saying that there will be human-sensed responses at part-throttle which will not be technically measurable at full-throttle? Further, that these responses will be attributable entirely to one leading brand of 98 octane as opposed to another leading brand of 98 octane, or indeed the same brand with different claims about lubricating qualities?
On the point "if it feels better, why not use it." I have no dispute at all, although perhaps I do not vest the comment with the same import as you appear to do. Have fun. It is what we are here to do
Saturday, October 28, 2006 - 11:51 pm, by: Dominic Kelly(Drk_awd)
Yes, I am saying that there are differences in response with different fuels at part throttle that may or may not be reflected in WOT performance.
This is only relevant to those with aftermarket engine management but with the correct equipment (a/f meter, knock detection and a dyno) a tuner may often notice the difference between fuel A and fuel B at certain load points when mapping or remapping the ignition curve for light load (under vacuum).
If fuel A was able to take say another 0.5 degree of advance under those conditions than fuel B even though both are rated at 98 RON then yes, some/most drivers may notice the difference even without a dyno.
It's this light load/part throttle mapping that separates a good tuner from one who is only interested in a big number on a dyno chart.
I've had my car tuned at various times by three respected tuners here in Brisbane and all have commented that BP Ultimate was slightly superior in that regard to Optimax. That was before Synergy 8000/Vortex 98/Optimax Extreme became available up here. Haven't asked their opinions on those fuels.
Anyway I digress - even if there were no differences in ignition advance, at certain load points one formulation may result in more complete combustion than another eg. superior flame front propagation. This will result in an increase in torque which may sometimes be quite noticeable (and measurable with the right equipment).
I hadn't read the V-Power blurb on the Shell website until now. It seems this FMT is used in the new V-Power Racing as well (the Optimax Extreme replacement).
I filled up a half empty tank the other day so roughly a 50/50 mix of the old and new. "Seat of the pants" dyno doesn't pick up any difference but I wonder if it might explain why my car is now running richer at high load/high rpm. I have a wideband O2 sensor and logging enabled and noticed it's now getting down to 0.79 lambda vs 0.80-0.81 previously. That's an afr of 11.6 vs 11.8-11.9 that it used to run.
Anyway, too early to tell. I'll leave it until I get a full tank of the new stuff. and check again.
Sunday, October 29, 2006 - 02:01 pm, by: Cihan Aday(Cihan)
If anything it would run leaner because of the alcohol.
Also, consider that different ambient temperature, humidity and barometric pressure contribute to AFR changes. The stock ecu takes care of the changes to some degree, less when we pull so much of the fuel with piggybacks.
I wasn't clear in my post - it was already tuned for Optimax Extreme. Adding half a tank of the new formulation to the older Optimax Extreme appears to have resulted in a slightly richer mixture than before. As I said though I'll wait until I've got consistent results from a couple of tanks before I can draw any conclusions.
I don't have a stock ecu and I do try to compare logs at the same engine and air temperatures.
No point running the Optimax Extreme/V-Power Racing in most cars as they can't really take full advantage of it. I retuned the fuel and ignition curves on mine. Not a drop of any other fuel has been used in my car for nearly a year now so you could say I like it. My fuel economy hasn't suffered surprisingly in spite of having to increase fuel pulse widths by 2-5%. I've increased the ignition advance from 0.5-1.5 degrees (this is very conservative) and I've found the improvement in torque means I'm using less throttle under cruise and light acceleration.
I've read where some of the Subaru and Nissan GTR owners have been getting good results from it. It really just depends on the car.
There is another thread where it was claimed that BP Ultimate was "at least" 98 whereas Shell was "up to" 98. On query, that proved to be hearsay; repetition of an unfounded claim already made on the forum.
Then there was a claim that BP Ultimate was refined to 100-101 Octane so it was 98 at the pump (no, you work out the temporal juggling). I queried that at 7.30pm last Thursday and have yet to hear a cheep of justification for the claim.
Above, I asked for evidence other than hearsay or personal opinion since which I have read a lot of ... hearsay and personal opinion. Guess what? My tuner disagrees with your tuner. So there!
Now we are to believe that the difference is found only at part throttle. I do not suppose that marginal differences in road slope and smoothness, amount of throttle and differences in ECU response would be a few new variables here, would they? You know, additional to more influential factors like whether you had sex last night.
I am more than ready to accept any claim of this nature, as anyone who actually knows me will attest. All that it will take in this instance is an absolute minimum of five tests of each fuel type under controlled atmospheric conditions, randomly sequenced and double-blind (i.e. neither the experimenter nor tuner knows which fuel is being tested at the time). Then show a statistical difference in the results.
Note that I have at no point discussed valid differences between 98 and 100 octane fuels and even in 98 octanes am restricting the discussion to leading brands such as we have already mentioned..
You can be as sceptical as you wish David that's up to you.
As for marginal differences in road slope and smoothness - don't you think people have favourite stretches of road they use all the time? For example the same hill I drive up every day on my way to work? Unless there has been a recent seismic event I don't think slope or smoothness come into it.
Throttle position? I have a Motec which just happens to be able to log that parameter (as well a manifold pressure) and I'm surprisingly quite consistent when travelling over familiar roads. From those logs I can also get a good idea from the slope of the rpm vs time data whether the car is in fact accelerating faster.
Sex? Well the fact you scored one for the first time in a couple of months might affect your driving but don't assume that's the case with the rest of us.
As for the octane rating an Autospeed article quoted a senior BP fuel chemist thus "Keep in mind that typical variation in BP Ultimate is 98 – 100 RON while normal unleaded ranges between 91 – 93 RON." So you can scratch that off your list as of approximately 12.15am, Tuesday 31 October. Sorry you had to wait so long.
Besides this, since when do we need to seek your approval for any of our opinions? Tell you what why don't you pay for an engine to be tested on an engine dyno and I'll supply the different fuels. Nice controlled environment and we should be able to vary the loads quite nicely. Double blind tests, random sequence the lot.
Not interested? No, didn't think so and mostly because of what it would cost. Given such a situation most of us rely on other less scientific but possibly still valid methods. No one here is making claims that they think fuel A has made an x% increase in the power at the wheels based on their drive down to the local Maccas.
Most drivers who are familiar with the way their car performs can usually notice when the car is running better eg. crisper throttle response and smoother running. If it happened after changing fuels and remains so consistently for a period of time and after eliminating other obvious factors such as a change in seasons or driving patterns then it is reasonable to assume that the fuel may have played a part in that.
Then again some drivers don't even notice they're driving with a flat tyre. In your case you'd probably want proof that the pressure in the tyre is in fact 0 psi before believing it. And only if the pressure gauge had been recently calibrated at a certified testing laboratory.
Sorry if I sound cranky but your smugness and patronising attitude are starting to piss me off. I understand that scientific methods are important but due to practicality and cost you often have to rely on your own senses and observations while trying to stay as objective as possible. Not easy of course but just don't assume we're all deluded fools because we try.
Interesting that you resorted to ad hominem attacks (and all of them risible ones at that) repeatedly throughout your response. It could not be that you were expressing personal prejudices rather than a shred of information, could it? I did not assert nor do I believe you are a deluded fool but rather than you are over-stating your position by use of hearsay and opinion as if they were facts and therefore potentially misleading others.
On the single fact you assert, that a BP senior fuel chemist said "...typical variation in BP Ultimate is 98-100 RON", that is not the statement previously made which I suggested was spurious, nor is it a statement which distinguishes BP fuel from Mobil or Shell in any respect. So, as of 12:15AM Tuesday 13 October, you continue to indulge flights of fancy in defence of a position, superiority of BP Ultimate over Shell Optimax or V-Power, for which you have no data other than your sensory perception and supportive but equally unsupported opinions of others. You are welcome to that position but all I ask is that you do not pretend it is more than that.
I have written extensively about this because I see no value in confusing articles of faith with matters of fact. If, for example, another reader here were to pay more for BP than for Shell or Mobil owing to belief in your seat of the pants, then they are welcome to their faith but objectively you have most probably assisted them to waste their money. If they do it based on their own faith then I expect they will be highly satisfied and I will at most point out in passing that they might like to re-think. There is nothing in that view by me that is either smug or patronising, merely helpful in making clear to others differences between opinion and fact.
On the question of paying for a test, it ought to have been reasonably clear that my point was that no test data has been presented, not that you, me or anyone else should be obliged to make the test. If your challenge is absolutely serious rather than another handle with which to manufacture a false attack then I will of course meet you on a 50-50 basis, much as I consider it will be a complete waste of money. We can each make payment to a third party prior to the test. If you decline, I will consider that sensible and not something by which to disrespect you so it would be better were you to drop it.
Wednesday, November 01, 2006 - 12:37 am, by: Dominic Kelly(Drk_awd)
If you found my post too personal then I apologise. As for everything else that was said I don't believe I am over-stating my position by hearsay. I passed on information gleaned from conversations with three respected tuners. These are guys whose workshops are full of Carrera Cup Porsches, Lambos etc. and know what they are talking about. The dyno, wideband O2 meter and laptop are their tools of trade. In fact who suggested using a dyno to gather proof? Oh that's right
David Vaughan: "Why does it confirm that? Has anyone tried a dyno rather than hearsay or their own opinion to compare 98-octane fuels?"
When I pass on the opinions of three men who are dyno tuning cars all day long that somehow becomes hearsay to you. Sorry if I didn't ask them for copies of dyno graphs but I accepted what they said without demanding proof. Would you have done the same?
If you're curious here's a link to a racing fuel site where they publish results of comparisons they made between Elf 98 RON race fuel, Optimax Extreme 100 RON, BP Ultimate and Optimax. The results were in that order. These people obviously aren't neutral as they're in the business of selling Elf racing fuel. Their main goal was to prove the superiority of the Elf 98 over the new threat of a 100RON pump fuel. Still, looking at the published torque and power curves you can clearly see that Ultimate produced higher torque figures (in that particular engine) than Optimax especially between 2000 rpm and 4000 rpm. No, not double blind and not sure how well controlled the conditions were but you suggested the dyno as proof and that's as good as you get with a dyno.
You seem to think I'm pushing BP Ultimate which is rather curious as I don't actually use it in either of my cars any longer. That's despite the fact a BP is my closest service station. As it so happens I use Shell Optimax Extreme/V-Power Racing in my Soarer. I clearly stated in my earlier post that I didn't ask the tuners' opinions on other fuels such as Synergy, Vortex98 or Optimax Extreme as none of those were available in Brisbane at the time.
I have never recommended any particular fuel to anyone. In a previous thread I stated that I found my Forester GT has noticeably improved fuel economy and seems slightly more responsive when using Vortex 98 - that was not a recommendation, just an observation. In this thread I have merely passed on the opinions of people who would know - certainly more than either of us. None of them are in the business of selling fuel and have no incentive to push one brand over another. Accusing me of assisting people to waste their money is quite laughable and clearly false.
My quote of the BP chemist was purely in response to your statement: "Then there was a claim that BP Ultimate was refined to 100-101 Octane so it was 98 at the pump (no, you work out the temporal juggling). I queried that at 7.30pm last Thursday and have yet to hear a cheep of justification for the claim."
You demanded an answer so I gave it to you. I don't know who originally made that claim and please show me where I have used it to assert the superiority of Ultimate over any of the Shell products (or any others).
As for not having any data - I have an ecu with logging capability. Able to log a number of parameters at either 10 or 20 samples per second. I have used this in the past to confirm that Optimax Extreme definitely allowed the car to produce more power than Ultimate (sharper slope on the rpm vs time curve ie. revs rose more quickly).
Regardless of the fact I can log data, the main point of my previous posts was to assert that given the inability to scientifically measure changes in a car's performance it is still possible to rely on sensory perceptions especially in a vehicle you know well and travelling on roads you use every day. You can use techniques such as speed at certain marker points as a guide.
You have twisted what I've said and combined it with statements made by others to make it look like I'm some travelling BP salesman peddling snake oil.
You've also missed the point of my suggestion that you pay for an engine dyno and chose to dramatise it as a false attack. Of course I don't expect you to pay for it - the reason there isn't a lot of hard data out there is because it's very difficult and expensive to provide the evidence you seem to demand of anyone who expresses an opinion or shares their observations with others.
You're very quick to throw the burden of proof on to others but how about you provide some evidence that there is no difference at all between the 98 RON fuels when used in vehicles capable of taking advantage of the higher octane rating?
Imagine if, for example, a reader here were to purchase Optimax rather than BP or Mobil owing to your belief there is no difference at all between the fuels and suffered reduced fuel economy and lessened driveability, objectively you have most probably assisted them to waste their money.
Wednesday, November 01, 2006 - 07:00 pm, by: Miles Baker(Milesb)
Look I can't be bothered reading all that stuff, but I'll throw in my 2 cents on the bit I did read. I used to ride a bike with 12:1 compression. With both Optimax and Mobil 8000, the WOT power on the dyno was the same. But both on the road and on the track, part throttle response was noticeably better with 8000. And trust me, on a bike, you can tell. From what I could tell by asking a mate who worked as an octane tester at a refinery, it could have been a different additive package. Buggered if I know what difference there is, but it was night and day on the bike. Optimax felt like fouled plugs. I wouldn't put it in the bike after I realised and confirmed that's what it was. And yes, I tried multiple petrol stations and it was over a period of months.