RE: Tescos 99 wins fuel shootout
Discussion
excelent thread
but sadly in the Netherlands we have V-power Ron97...and in Germany they have V-power Ron100...its not fare and you realy can feel that in your car! I have driven both and the Ron100 is much better! I called shell NL they say...yeah but the germans drive faster thats why they have Ron100?? what a lot of bullshit
I like to have the Ron100 too but sadly they don't dare...?
GTRene
but sadly in the Netherlands we have V-power Ron97...and in Germany they have V-power Ron100...its not fare and you realy can feel that in your car! I have driven both and the Ron100 is much better! I called shell NL they say...yeah but the germans drive faster thats why they have Ron100?? what a lot of bullshit I like to have the Ron100 too but sadly they don't dare...? GTRene
My thoughts (not entirely scientific), all with a Clio 172 Cup...
Optimax/V-Power - nearest station 20 miles away (Castle Combe), not tested.
BP Ultimate - Currently 112.9p, so couldn't care less if it gave me a 30bhp increase.
Tesco 99 - Not rolled out locally. Tried twice whilst on holiday and noticed considerable reduction in MPG.
Conclusion: bring some decent fuel to Wiltshire! I'll buy it!
Optimax/V-Power - nearest station 20 miles away (Castle Combe), not tested.
BP Ultimate - Currently 112.9p, so couldn't care less if it gave me a 30bhp increase.
Tesco 99 - Not rolled out locally. Tried twice whilst on holiday and noticed considerable reduction in MPG.
Conclusion: bring some decent fuel to Wiltshire! I'll buy it!
This is the first test I have ever seen where a car mapped for 95RON fuel (the MR2) made more power on higher octane fuel.
This goes against what I thought was the conventional wisdom, that putting super unleaded in a car that was mapped for 95RON and could not advance the ignition timing would not yield any increase in power or economy. The tests that Autoexpress and Fifth Gear did showed a slight drop in power, due (I believe) to the octane boosting components containing less energy than the base fuel. For example, bio-ethanol contains less enerygy than unleaded which without mapping changes should result in a drop in economy. This other PH article makes interesting reading: www.pistonheads.com/lotus/default.asp?storyId=14861
It goes without saying that 99 octane fuel is best if you car has an ignition map for it, but I'm suprised to see these benefits on a car mapped for 95RON.
milesr3
This goes against what I thought was the conventional wisdom, that putting super unleaded in a car that was mapped for 95RON and could not advance the ignition timing would not yield any increase in power or economy. The tests that Autoexpress and Fifth Gear did showed a slight drop in power, due (I believe) to the octane boosting components containing less energy than the base fuel. For example, bio-ethanol contains less enerygy than unleaded which without mapping changes should result in a drop in economy. This other PH article makes interesting reading: www.pistonheads.com/lotus/default.asp?storyId=14861
It goes without saying that 99 octane fuel is best if you car has an ignition map for it, but I'm suprised to see these benefits on a car mapped for 95RON.
milesr3
Well Done to TMC for even attempting such a test, given all the possable variables in trying to achive accurate results over such a long period time.But given the amount of differant engine configs in use today I.e Combustion shapes,compression ratios,engine management systems,forced induction or N/A ETC ETC.If you have tried all the super unleaded's on the market and a certain brand feels the best under your right foot and your fuel gauge takes longer to fall into the red than thats what its good for you!These tests make good for reading but should not to be taken as gospel.
to me, regardless of the test results, the article just looked like and advert for the garage doing the testing and the makers of the rolling road!
it was almost condecending in the way it explained simple facts like "we put the rolling road on the floor so we can put race cars on"...um where else are you going to put it? the fans make it like wind tunnel!....give me a break!
interesting results, but poor journalism in the extreme!
it was almost condecending in the way it explained simple facts like "we put the rolling road on the floor so we can put race cars on"...um where else are you going to put it? the fans make it like wind tunnel!....give me a break!
interesting results, but poor journalism in the extreme!
eccles, sorry if you feel that way. The reason why I wrote it that way is that we wanted to explain to the non car enthusiasts out there. I must have dumbed it down 100 fold to get it to that level or I'd have banged on about air fule rations and ignition timing for 10 pages and 99% of the World would've switched off. Sorry if it seems a bit of an advert for TMS but no-one paid us for this, we did it of our own account as we genuinely curious as to the result and no-one else had ever tried this level of testing. I think it reasonable we at least gain something from the report by way of PR but appreciate your opinion if you think it detracted from the central issue.
The reason for the placement of the dyno is actually not as obvious as you'd think. Most dynos are actually in floor mounted, ie they're dug into the ground, however we found that with rear engined cars you can't get under floor airflow to the engine bay when the car drops down into the rollers so we deliberately surface mounted it, this allows the airflow to run under the chassis. Also, by surface mounting the dyno we can strap through the dyno itself vertically up to the cars chassis rather than strap accross the car or the bodywork. Did you see the thread here recently with people literally sitting on the rear of a Lotus Esprit to get it to grip the rollers - bad idea as it directly affects the reading and isn't exactly the safest way to strap a car down!
We were just as surprised as some here on the effect on the MR2. Conventional wisdom always stated that even modern cars can only advance their ignition a very small level to account for higher octane fuel whereas they can retard a lot further as its a self defence mechanism on the engine. Obviously remapped cars use a wider variance on this process so the CSL is less of a surprise (we are now testing a standard CSL in the same way) but the tests did show that the MR2 was able to advance the ignition to such an extent to take advantage of the higher octane fuel.
The reason for the placement of the dyno is actually not as obvious as you'd think. Most dynos are actually in floor mounted, ie they're dug into the ground, however we found that with rear engined cars you can't get under floor airflow to the engine bay when the car drops down into the rollers so we deliberately surface mounted it, this allows the airflow to run under the chassis. Also, by surface mounting the dyno we can strap through the dyno itself vertically up to the cars chassis rather than strap accross the car or the bodywork. Did you see the thread here recently with people literally sitting on the rear of a Lotus Esprit to get it to grip the rollers - bad idea as it directly affects the reading and isn't exactly the safest way to strap a car down!
We were just as surprised as some here on the effect on the MR2. Conventional wisdom always stated that even modern cars can only advance their ignition a very small level to account for higher octane fuel whereas they can retard a lot further as its a self defence mechanism on the engine. Obviously remapped cars use a wider variance on this process so the CSL is less of a surprise (we are now testing a standard CSL in the same way) but the tests did show that the MR2 was able to advance the ignition to such an extent to take advantage of the higher octane fuel.
John,
I think you'll find that conventional wisdom wrt the importance of ignition advance is simply wrong. It doesn't account for variations in flame speed, and it ignores the importance of air fuel ratio. Oxygenated fuels can provide more power because you can burn a greater mass of fuel for a given mass of induced air. To achieve that, you don't need trick ignition control, you just need a lambda control loop.
The chart shows 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.
I hope I misunderstand, but that reads like bull to me. Did you measure HC, CO or otherwise try to establish the "efficiency of burn"? FWIW, in case it's useful, I'd suggest that you investigate the correlation of fuel density and oxygen content with AFR differences. As to using less fuel at high rpm's, do you seriously map your engines to run lean at high engine speeds?
WilliBetz
I think you'll find that conventional wisdom wrt the importance of ignition advance is simply wrong. It doesn't account for variations in flame speed, and it ignores the importance of air fuel ratio. Oxygenated fuels can provide more power because you can burn a greater mass of fuel for a given mass of induced air. To achieve that, you don't need trick ignition control, you just need a lambda control loop.
Thorney said:
The chart shows 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.
I hope I misunderstand, but that reads like bull to me. Did you measure HC, CO or otherwise try to establish the "efficiency of burn"? FWIW, in case it's useful, I'd suggest that you investigate the correlation of fuel density and oxygen content with AFR differences. As to using less fuel at high rpm's, do you seriously map your engines to run lean at high engine speeds?
WilliBetz
thorney said:
the tests did show that the MR2 was able to advance the ignition to such an extent to take advantage of the higher octane fuel.
OK, that makes all the difference - I thought that the MR2 didn't have a knock sensor and had a static ignition map. How was it able to advance the ignition? I read the article as if it was a car mapped for 95RON making more power on super unleaded, which goes against conventional wisdom. It would have been interesting to have included a really old car (like my BMW E34 M5) in this study.
I'd also like to add my thanks for the time and effort that has gone into this! I'd also encourage you to continue testing with V-Power and write the 10 pages too as lots of people (myself included) don't understand this and would like to know more.
Thanks again,
milesr3
thorney,
thanks for your explanation of the dyno mounting, it would have been nice to see it in the article.
i just thought the whole article was dumbed down to an extent it was almost silly. if it was written just for pistonheads, you'd have to assume the majority of people who visit the site are into their cars etc, and wouldn't need it dumbing down, however if it was written for general release i could understand it .
thanks for your explanation of the dyno mounting, it would have been nice to see it in the article.
i just thought the whole article was dumbed down to an extent it was almost silly. if it was written just for pistonheads, you'd have to assume the majority of people who visit the site are into their cars etc, and wouldn't need it dumbing down, however if it was written for general release i could understand it .
The background to the article is this. I moved TMS from West London to Milton Keynes in December last year but was commuting 100 miles a day in my CSL as I was stuck in a lease on my house until early 2006. Seeing as I was chewing through petrol at an alarming rate and seeing as Milton Keynes has several Tescos which all sell 99 octane fuel I thought I'd give it a go.
After a few runs I was convinced that the car felt faster on the Tesco fuel so when our dyno was delivered in 2006 we thought we'd have a play with that at the same time as actually test the fuels properly (no-one seems to have done more than a few runs). I saw the Tesco test on PH but seeing as they compared different cars I didn't give it much credence tbh. As the testing continued we were pretty amazed by the extent of the gains so it sort of ran out of control with us testing over an over again. Ambient temperatures and barometric pressure does affect the power reading of cars so as the weather changed we were keen to make sure we tested the cars in as near identical temps/pressures to keep it valid. During the hot weather we had it meant that we were coming in very early just to dyno the cars in similar pressures/temps. The Dyno Dynamics does equalise for this kind of variance but I wanted to be sure.
We finished the report, I wrote it up as best I could (I'm no jounalist) but I showed it to my parents who gave me long blank looks as to what I'd written so I wrote it again as simple as I could, I think this might have clouded some of the technical data as dumbing down tends to do.
Obviously we aren't a fully fledged fuel testing company, we're a tuning company, so we utilised the skills/equipment we have to measure what cars were doing on fuel bought from pumps - ie, in my opinion - real World testing. I certainly wouldn't look at the data and assume white coat levels of intracacy with fuel measurement and mpg equation but I do stand by the fact that its a measured process with repeatable reuslts.
After a few runs I was convinced that the car felt faster on the Tesco fuel so when our dyno was delivered in 2006 we thought we'd have a play with that at the same time as actually test the fuels properly (no-one seems to have done more than a few runs). I saw the Tesco test on PH but seeing as they compared different cars I didn't give it much credence tbh. As the testing continued we were pretty amazed by the extent of the gains so it sort of ran out of control with us testing over an over again. Ambient temperatures and barometric pressure does affect the power reading of cars so as the weather changed we were keen to make sure we tested the cars in as near identical temps/pressures to keep it valid. During the hot weather we had it meant that we were coming in very early just to dyno the cars in similar pressures/temps. The Dyno Dynamics does equalise for this kind of variance but I wanted to be sure.
We finished the report, I wrote it up as best I could (I'm no jounalist) but I showed it to my parents who gave me long blank looks as to what I'd written so I wrote it again as simple as I could, I think this might have clouded some of the technical data as dumbing down tends to do.
Obviously we aren't a fully fledged fuel testing company, we're a tuning company, so we utilised the skills/equipment we have to measure what cars were doing on fuel bought from pumps - ie, in my opinion - real World testing. I certainly wouldn't look at the data and assume white coat levels of intracacy with fuel measurement and mpg equation but I do stand by the fact that its a measured process with repeatable reuslts.
no problem mate, to be honest its nice to have people question these things otherwise we'd never get a chance to explain the detail behind it, which I think is sometimes more useful than the content itself.
By way as a follow up we're continuing with the testing with different cars and including the new V Power from shell (although this has actually already been tested as we've been on V Power since the end of June) but we'll include it formally. Its actually quite fun and doesn't actually cost us much in terms of cash as we're using the fuel anyway as part of our daily business, it is a pita keeping track of it all though, more than once I ran out of fuel on the Astra VXR (one of the other cars tested)
By way as a follow up we're continuing with the testing with different cars and including the new V Power from shell (although this has actually already been tested as we've been on V Power since the end of June) but we'll include it formally. Its actually quite fun and doesn't actually cost us much in terms of cash as we're using the fuel anyway as part of our daily business, it is a pita keeping track of it all though, more than once I ran out of fuel on the Astra VXR (one of the other cars tested)
LexSport said:
98 + 5% Ethanol at 114 RON or whatever it is, is I presume what gives you the 99 RON. IIRC, Shell and BP have their own refineries in the UK, all other fuel companies use the same refineries, but that's just for the raw fuel. The additive packages then added are unique to each brand.
Total have their own refinery in the UK as well.
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. 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!
Thorney, have you not considered the possibility that the Tesco 99 RON with it's ethanol content may affect the AFR and affect the power? Also, I didn't see anything in your report about measuring the ignition timing, so it's not really scientific enough if you ask me. For example, if the ignition timing was the same on the Tesco 99 RON as it was on the 95 RON, it's highly likely that the increase in power is coming from a chemical difference in the fuel blend and not the RON. Since you didn't measure this, the experiment doesn't actually explain anything. In summary, the test showed what happened, but not why it happened.
This article is more of an advertorial IMHO. And it's definately not a wind tunnel lol. those are desk fans
This article is more of an advertorial IMHO. And it's definately not a wind tunnel lol. those are desk fans
Edited by spode on Saturday 2nd September 01:54
We knew we'd ruffle a few feathers by doing this and I've no intention of dampening the right to anyones own opinion but all we can do is report what we found, I'm sure the conspiracy theorists hout there will have all kinds of other ideas on what happened.
Based on our own testing, to which I'm putting my company name (not some nameless post on a forum with an opinion) is that in the testing we did we did see the results as described, the fact anyone has another idea on what/whom/whatever goes into the fuel industry frankly has nothing to do with our testing but we stand by the results - can't say fairer that that can I.
You do make a valid point, yes, we do not have the equipment to tell people exactly why the different fuels perform differently, we're assuming its down to the octane rating and the respective blends but there is no way of knowing (and likely we'll never know, although I'm sure the fuel companies do) exactly which bit of the fuel blend makes the difference to power. For that reason we only make general comments on the actual fuel itself not on specific make ups within that fuel. However, as I've said we tested the fuels as they are sold and reported the results as we found them, if we'd said "the xyz additive of fuel Y is responsbible for the power gains" then I'd agree it would be a more valuable test but we simply don't have that kind of equipment. Like I said, we're a tuning company not a fuel testing agency.
As regards the desk fan comment - lol. If you'd seen what some tuning firms consider to be adequate cooling on dynos you'd realise that our set up really is head and shoulders over most. We know for a fact that 120,000cfm is the highest in the UK so I think we're justified in our statement. Of course its not an 'actual' wind tunnel but seeing as they cost £4m a pop I don't think thats unfair With all 4 fans going (we rarely need to use all 4) we exchange the entire contents of air in the cell every 5 seconds, the recommended industry minimum is every 17 seconds so we're well above that. However sorry if the comment upset you, perhaps you'd like to come down and we'll get you into one of our fan races......sit on a fan and it'll blow you accross the workshop floor at a frightening rate of knots!
Based on our own testing, to which I'm putting my company name (not some nameless post on a forum with an opinion) is that in the testing we did we did see the results as described, the fact anyone has another idea on what/whom/whatever goes into the fuel industry frankly has nothing to do with our testing but we stand by the results - can't say fairer that that can I.
You do make a valid point, yes, we do not have the equipment to tell people exactly why the different fuels perform differently, we're assuming its down to the octane rating and the respective blends but there is no way of knowing (and likely we'll never know, although I'm sure the fuel companies do) exactly which bit of the fuel blend makes the difference to power. For that reason we only make general comments on the actual fuel itself not on specific make ups within that fuel. However, as I've said we tested the fuels as they are sold and reported the results as we found them, if we'd said "the xyz additive of fuel Y is responsbible for the power gains" then I'd agree it would be a more valuable test but we simply don't have that kind of equipment. Like I said, we're a tuning company not a fuel testing agency.
As regards the desk fan comment - lol. If you'd seen what some tuning firms consider to be adequate cooling on dynos you'd realise that our set up really is head and shoulders over most. We know for a fact that 120,000cfm is the highest in the UK so I think we're justified in our statement. Of course its not an 'actual' wind tunnel but seeing as they cost £4m a pop I don't think thats unfair
With all 4 fans going (we rarely need to use all 4) we exchange the entire contents of air in the cell every 5 seconds, the recommended industry minimum is every 17 seconds so we're well above that. However sorry if the comment upset you, perhaps you'd like to come down and we'll get you into one of our fan races......sit on a fan and it'll blow you accross the workshop floor at a frightening rate of knots! 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.
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