RE: Tescos 99 wins fuel shootout

RE: Tescos 99 wins fuel shootout

Author
Discussion

spode

28 posts

218 months

Saturday 2nd September 2006
quotequote all
thorney said:
Like I said, we're a tuning company not a fuel testing agency.



Hmm, a good and experienced tuning company knows exactly what happens when you use oxygenated fuels so I can only assume you have little experience of this. That's no big issue, as long as you are able to acknowledge that.

targarama

14,635 posts

282 months

Saturday 2nd September 2006
quotequote all
spode said:
thorney said:
Like I said, we're a tuning company not a fuel testing agency.



Hmm, a good and experienced tuning company knows exactly what happens when you use oxygenated fuels so I can only assume you have little experience of this. That's no big issue, as long as you are able to acknowledge that.


Who are you Spode? You sound like you might know something about this stuff. How about letting people know who you are instead of being secretive? Might give substance to your comments then.

thorney

408 posts

259 months

Saturday 2nd September 2006
quotequote all
I didn't say we didn't know anything about oxygenated fuels, I simply said we lack the equipment to accruately point to what causes the difference in power measurement within the make up of the fuels themselves. To say as you suggest would be pure conjecture and I wanted to limit the report to simply what we discovered, the whys and wherefores are another matter.

As I've said, we've had to keep the report short and simple and that means certain data just gets left out.

willibetz

694 posts

221 months

Saturday 2nd September 2006
quotequote all
Thorney,

First and foremost, I don't dispute your results. They are in line with what I'd expect. Your test methods are strange to me (why on earth use different fuel stations and fill at different times of the day?), but they are your own business.

However, as spode points out, your explanation for why the results happened is deficient. Where you've speculated, and in particular when you pronounce:

thorney said:

the car’s ECU when running on 95 Octane fuel enriches the fuel mixture (adds fuel) to compensate for the less efficient burn and to avoid early detonation. This extra fuel robs power as the air/fuel mix is less efficient. By changing this fuel to a higher octane the car is able to advance the ignition (essentially using less fuel at higher rpm’s) to create more power.


... you've got it wrong. I only make the point because you profess to eschew bull in favour of honesty, integrity and meticulous testing. It's also pretty fundamental - if your analysis is flawed, any development that you do on the basis of your analysis will also be suspect. The result will be wasted development hours and possibly broken engines.

I'd suggest, if you would like to do some analysis, that you take note of fuel density, oxygen content, consumption (assuming you don't have a fuel balance, can you get this from the engine management / diagnostics?) and exhaust temperature and gas analysis.

I think you'll be able to reach a clearer understanding and explanation of your results, without recourse to more expensive kit.

Good luck,

WilliBetz

Thorney

408 posts

259 months

Saturday 2nd September 2006
quotequote all
Willi, we went to different fuel stations and different times of the day to stop any suggestion that we somehow had bad fuel or only used the same batch. I agree my explanation is simplified but I've tried to make it that way. That sentance you've take out referred to the air fuel ratio map that we included by way of a demonstration that is all. The fact is we actually don't know why the air/fuel ratio changed so dramatically on the cars with 95 octane fuel in them but it was consistent on all the cars so was worthy of comment. The testing is continuing with further investigation as to the actual reasons why the variance was different but I'd imagine that each cars ECU reacts differently and reset different parameters according to its programming so we're unlikely to come up with a if x = y then z is true.

anonymous-user

53 months

Saturday 2nd September 2006
quotequote all
spode said:
thorney said:
oh sorry, missed the bit on ignition timing. We did (and do) measure that but for our remapped cars its something that we develop for the tuning packages so its not something I'm ever going to make available, sorry. Fair point though.


All you needed to do was to state whether the ignition timing was the same or not, and if not, by how many degrees different. This would have given the results some credibility without giving away any secrets.


Agreed. The results for the MR2 in particular can be read as if they are saying that a car statically mapped for 95RON makes more power on 99RON, which shouldn't be happening.

AIUI the MR2 doesn't have a knock sensor, so how did it optimise its ignition timing?

milesr3

willibetz

694 posts

221 months

Sunday 3rd September 2006
quotequote all
Thorney said:
Willi, we went to different fuel stations and different times of the day to stop any suggestion that we somehow had bad fuel or only used the same batch.


Thanks for the explanation. Unfortunately, I'd take the contrarian view that you've multiplied your chance of drawing "bad" fuel and, at the same time, invalidated your control or baseline.

I understand that you're running these cars as daily drivers, so filling them repeatedly to clear previous fuel and allow the engine management to adjust isn't a major pain. But have you considered rigging a second fuel tank to one of your cars to allow you to explore the dynamic impact of switching from control fuel a to test fuel b?

WilliBetz

thorney

408 posts

259 months

Sunday 3rd September 2006
quotequote all
Willi, true. We wanted this to be as representative of peoples everyday lives as possible and seeing as we didn't solicit any payment from anyone I guess I wanted to keep the actual management cost down as low as possible.

With hindsight the testing would have greater empirical data if we did as you suggest and I especially agree with the multiple tank idea and the sending away of the fuel at each stage for testing as it was drawn(as who knows that you actually get when you stop at a service station) but I guess I was loathe to really spend large amounts of hard cash on a test that we did primarily for our won thought process's as much as anything.

Your comments have started a chain of thought going here though in that so vey little is actually known about the fuels we put in our cars and whilst the fuel companies spend billions testing (I assume) non of this data is available to the public. Greenergy publsih their blend on their site but how much value is this for people? I imagine not much but its a lot more than the main suppliers sho just seem to publsih the marketing.

With a bit of luck maybe this kind of basic testing report will jog one of the more formal testing companies to conduct an open test on all the fuels and publish that but I doubt it'll happen, at the end of the day this is big bucks to these guys so there would be too many vested interests. I'm just glad we did something more than just assume things were better/worse and backed that up with open testing, I'd liked to have done more and we will continue the testing purely for our own curiousity with Vpower etc but end of the day this isn't our role.

bobdylan

574 posts

210 months

Monday 4th September 2006
quotequote all
BP ultimate 102 !!!!!!!!!!!!!
at £2.40 a liter !!!! its not cheep but its good stuff. porsche 996 gt3 rolled 381bhp . with the new bp it rolled 406bhp. 25 extra ponys. better yet when they mapped ECU too run purely on 102 it made 430bhp !!!!!!!
thats a 12.5% gain. 48 extra ponys from a tank of gas rotate . 48bhp is a good gain from expensive engine mods never mine a full tank.
question is tho.....£2.40 a liter , is it worth 12.5% ?
work out how mutch it would cost to fill your tank and what your gain would be ?

Edited by bobdylan on Monday 4th September 00:44

cptsideways

13,535 posts

251 months

Monday 4th September 2006
quotequote all
Neilpeel59 said:
Sorry to put a dampener on all this but....
1. Tesco do not make a single drop of fuel (they have no refinery)
2. 99 octane will only be of benefit if your engine has compression ratio high enough to take advantage of that.
3. The only thing that will differentiate fuel is the additives they bung in ex refinery and this is marginal to say the least.
4. An oil refinery is a big hot stinky old thing. One day the fuel is at the top of the spec the next it just about meets the minimum requirement of BS EN228. Either way it ends up on the forecourt, Tesco, Morrisons whatever.
5. These tests are meaningless.
6. I'll stop now, I'm sending myself to sleep!


Wrong!!!!

1: The fuel is made by a company called Greenergy from biomass products
2: If you reduce the fuels RON rating sufficiently enough every engine will detonate at a certain point, so a fixed c/r has little to do with it. Increasing RON allows the same engine to increase to increase its det point.
3: Sort of correct
4: Hence why first delivereies of V-power is 102 RON, as they are topping up the optimax tanks
5: No they are not, most modern cars have ECU's capapble of refuelling & or advancing the ignition to some degree, just some like VAG/Porsche/Subaru the variabilty is rather larger than other manufacturers.

My 1988 (yes nearly 20 years old) Toyota Twin Turbo was designed with such features & mapped for 100RON fuel. Though I assume later Toyota's may be far more advanced. It runs like a diesel tractor on 95 in comparison to 99 stuff.

anonymous-user

53 months

Monday 4th September 2006
quotequote all
I just had a look at Greenergy's fuel quality results for their 99RON fuel.

It has 2.7% oxygen content, which presumebly makes it burn the charge more effectively and release more power with fuelling changes alone? Hence the differences in AFR in the article?

I also noticed that it has a density of 0.75 and IIRC Optimax was kept at 0.74 so as to not overfuel engines with carbs or without lambda control.

milesr3

dandarez

13,246 posts

282 months

Monday 4th September 2006
quotequote all
thorney said:
We wanted this to be as representative of peoples everyday lives as possible and seeing as we didn't solicit any payment from anyone I guess I wanted to keep the actual management cost down as low as possible.


Did you though get 'free' shopping for a year at Tesco? laughlaughlaughlaugh

bobdylan

574 posts

210 months

Monday 4th September 2006
quotequote all
(EVO) "the new bp102 contains a high performace bio-content that isnt bioethanol. its the only automotive petrol not classed as carcinogenic. it will also change formulations for winter / summer" .
102RON.
question, if this new fuel ofers 12% how will it effect controled motorsport events that use pump fule ?

darkblueturbo

109 posts

211 months

Monday 4th September 2006
quotequote all
Sorry to break up the discussion but to answer an earlier query from myself and A.N. Other about does Tesco99 have cleaning additives a la V-Power...

www. greenergy.com says:
"Tesco 99 Octane also contains low levels of olefinic compounds, typically less than 5%, compared with up to 18% in standard petrols. These compounds can lead to the creation of engine deposits. To ensure Tesco 99 Octane remains ‘cleaner’ petrol, an additive package is included with twice the protective power of typical 95 octane fuel. It removes existing deposits and helps the engine to run more smoothly."

fwdracer

3,564 posts

223 months

Monday 4th September 2006
quotequote all
bobdylan said:
(EVO) "the new bp102 contains a high performace bio-content that isnt bioethanol. its the only automotive petrol not classed as carcinogenic. it will also change formulations for winter / summer" .
102RON.
question, if this new fuel ofers 12% how will it effect controled motorsport events that use pump fule ?


See previous thread: It would appear that while BP102 doesn't match the 'footprint' for "pump" fuel as mandated by the RAC - Tesco's 99 does....

www.pistonheads.com/gassing/topic.asp?t=300285&f=57&h=0

Back to the debate on the test methodology. To be a trully comparitive it would require just one single variable to be changed (the fuel). Same car, same rollers, same day. Then it is worth noting that the only true comparison is whether the vehcile learns the new fuel via EMS software algorithm change (hence software compensation leads to greater power/torque), or in the case of the more traditional cars, whether the dizzy can be swung to run with more ignition advance and greater power or torque is created. Either way, it is about your car being optimised to run on the fuel, otherwise I'm afraid the greatest affect is placebo.

Edited by fwdracer on Monday 4th September 12:59

willibetz

694 posts

221 months

Monday 4th September 2006
quotequote all
fwdracer said:
[Back to the debate on the test methodology. To be a trully comparitive it would require just one single variable to be changed (the fuel). Same car, same rollers, same day.


Unfortunately, the influence of atmospheric pressure, humidity and temperature, as well as engine oil and water temperature are such that even same day back-to-back testing isn't enough.

Given the purpose and equipment, the test methodology proposed by Thorney seems fair enough to me.

WilliBetz

AlexS

1,550 posts

231 months

Monday 4th September 2006
quotequote all
Neilpeel59 said:
Sorry to put a dampener on all this but....
1. Tesco do not make a single drop of fuel (they have no refinery)
2. 99 octane will only be of benefit if your engine has compression ratio high enough to take advantage of that.
3. The only thing that will differentiate fuel is the additives they bung in ex refinery and this is marginal to say the least.
4. An oil refinery is a big hot stinky old thing. One day the fuel is at the top of the spec the next it just about meets the minimum requirement of BS EN228. Either way it ends up on the forecourt, Tesco, Morrisons whatever.
5. These tests are meaningless.
6. I'll stop now, I'm sending myself to sleep!


1. Maybe, but Tescos do have exclusive use of the Greenergy fuels.
2. Many performance cars are det limited, rather than reaching the point of max power for min timing. Increasing the octane will allow the timing to be advanced. High octane fuel can also allow turbos (especially) to maintain a safe headroom over det on very hot days.
3. Tesco 99, Shell Optimax/V-Power and BP 102 are all made from their own unique base stocks. Other Supers use a common base, but there are still significant differences between the fuels, Evos can take good timing on the 'standard' BP Ultimate compared to the use of other supers.
4. Hopefully by the large number of repeat tests the variability in Octane will be accounted for. The variability is also limited anyway by the British Standards.
5. The tests do show that the use of high octane fuel is worth it. Hopefully these (and others Evo, Fifth Gear etc) will show the general public that there is a point in using the expensive fuels in performance cars. I've had a right earful in the past for stopping at the closest pump instead of moving the car forwards as it was the only one of the two with a working super pump.

ringram

14,700 posts

247 months

Saturday 23rd September 2006
quotequote all
Has anyone commented on the fact that to take best advantage of the fuel used timing should be altered. Lower octane fuels have more energy potential and require less timing. Higer octane fuels burn with less energy, but allow more timing to be used.
Optimal timing is realised with peak cylinder pressure arriving somewhere around 14* ATDC. What you are looking to do is to reduce combustion pressure BTDC and place it all ATDC, less timing is better for this. Newer engines need less timing.

There are too many variables involved. It may well be the case that factory timing is too far advanced for standard fuels. Also many engines use long term knock corrections. The VXR monaro is one such example. KR will pull timing from the engine permanently in some instances. Higher octane will reduce the propensity to knock and therefore allow timing to return to factory optimal.

IMO, a better test would be to tune the car in on a dyno properly for each fuel. That would be the best test. Failing to retune the engine for each fuel is a pointless exercise.

nooner

2 posts

210 months

Monday 25th September 2006
quotequote all
Optimax IS v-power. Bought some in Ireland in may. Euro name. Like Marathon/Snickers

IT10

602 posts

214 months

Thursday 28th September 2006
quotequote all
nooner said:
Optimax IS v-power. Bought some in Ireland in may. Euro name. Like Marathon/Snickers


I',m sure the octane rating increased in V Power over Optimax at least here in England, so it isn't the same stuff...