Oh yes,
I'm well aware of the implications of Octane rating and the issues regarding Optimax and Octane degradation.
However, at the moment, I'm just looking at the difference between Happy Shopper 95 Premium and Shell/Texaco/Esso/BP 95 Premium.
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If I can summarise this correctly, the position is believed to be that all fuel meets a minimum British Standard. Fuel comes in bulk from various refineries, none of which are owned by supermarkets SFAIK. The difference, where if is one, is down to the quantity and quality of the additives which are added to the fuel, at the point of delivery, by the tanker drivers. So, all the fuel is good enough to meet the minimum legal standards and then is or is not improved, depending on what you believe, by the addition of additives which increase the price and may or may not improve performance, engine cleanliness, and mpg.
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8< SNIP 8< nothing offensive said, just cleaning up the thread from an earlier comment made - DD
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Perhaps the huge number of threads you will find can be short circuited a little;
There's no-one on here who *knows* the answer, bacuase no-one has done any sufficiently scientific test to be sure and certain of their results.
There's plenty of thoughts and opinions, expressing just about every point of view on the subject.
The understanding gained via some fuel delivery drivers is that the raw fuel is the all the same, but just the additives are different (except perhaps Optimax).
The best advice I could give would be to run your car for a few months on one brand, noting milage and the total No of litres - then, change brands, and see what difference you notice - please report your findings back here - they will count for much more than the pages of hot air you might read on the subject.
My own view? - The car gets filled up by whichever fuel happens to be available when the needle is reading low - fuel has to meet standards, and I would much rather buy premium real ale or red wine rather than petrol, which all tastes awful!! ;-)
Cheers,
Number_Cruncher
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Thanks for the replies.
I tend to use a random mix of big name stuff and supermarket fuel. Years ago when I had a car that pinked on 95 and I didn't want to retard the timing, I found that one tank of 98 Super for 3 tanks of 95 was enough to sort the problem. Then when I became interested in performance cars I used Opticrap and Super exclusively. Nowadays I'm too tight and I don't think it's worth it. Actually, the car (1990 BMW 318iS) doesn't have enough power for me to care about the difference in power output possible, but I am interested in mpg.
Anyway, I intend to keep records of my fuel use over the next year or two and I'll be able to build up statistical data and then look for any correlation between brand and mpg.
Re the additives, stuff like Millers Octane booster is reckoned to work, so the additives could well make a decent difference. Then there's the question about whether it's cheaper to add your own.
Thinking randomly, a work colleague used to buy in Acetone to add to his fuel as an Octane booster.
I've done some searching, but TBH I've not located any decent threads yet.
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I'm doing a test at the moment. A full tank of BP Ultimate Diesel and careful driving. Best I've ever achieved on normal diesel is 51, so I'll be looking to beat that. If I don't, then I shall formally pronounce it rubbish and good marketing.
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One tankfull David? - Who are you so wise in the ways of science?
Number_Cruncher
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I find it incredible (and I use the word advisedly) that Which, or some other such organisation have never deigned to carry out a scientific test on supermarket versus branded fuel. I could design various tests they should be doing, from fuel consumption to deposits over a few thousand miles.
And the reason I can't believe it? They will happily spend time and effort on tests of washing machines, dishwashers, exterior paint, etc, which are all once-every-five-years purchases at most, but they don't seem interested in testing something that 90% of their readership must buy every week, and that must cost far more in a year than any washing machine.
I wrote to them and never even had the courtesy of a reply (just the sort of behaviour they condemn in others). I cancelled my subscription because of it.
They are obviously too busy comparing the sugar content of Baked Beans (I kid you not, they do that) to bother with a test that might be useful to their readers.
V
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8< SNIP 8< nothing offensive said, just cleaning up the thread from an earlier comment made - DD
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Vin, I think a meaningfull Which type test on fuels would be a major undertaking and very costly. You will recall the Channel 5 did some tests on a rolling road re Optimax and the results were no effect on a small car, a bit of extra bhp in a Golf and about 30 extra in an Impreza. If they ever di dsuch a test it might be interesting to check out the effect of a/c on consumption, an often discussed matter here! The conspiracy theorists, of whom I am not one, might think that the big name companies would not want the tests as it might show that their high priced fuel has no measurable advantage over the cheap stuff!
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" Vin, I think a meaningfull Which type test on fuels would be a major undertaking and very costly. "
Maybe so, but it would affect their readerships pockets more than their usual tests. They pool information with consumer organisations across Europe, so could surely pool for this one - after all, there must be cheap/expensive fuels in Europe.
At least for the mpg test, I reckon the test would not be so expensive; piggybacking on an official fuel economy test would allow them to do it. All it would take is a word with the manufacturer (who would probably do it for the publicity) plus a few tanks of fuel per model. Test three models; low performance, medium and high - see if there's any difference in economy on the three.
By the way, my anecdotal evidence is that 100,000 miles in an Omega on almost exclusively Tesco's best didn't appear to cause any problems at all. My test of Optimax (it's on the forum somewhere) showed no change in consumption.
V
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One tankfull David? - Who are you so wise in the ways of science? Number_Cruncher
At 104p per litre one tankful is all I'm going to try in case it doesn't work!! Needless to say, if it does show promise then I'll try again.
Obviously, I'm happy to repeat the tests as often as necessary if you make up the difference between the bog standard and premium. Cheques are fine, though I would prefer non-sequential notes in small brown envelopes.
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Obviously, I'm happy to repeat the tests as often as necessary if you make up the difference between the bog standard and premium. Cheques are fine, though I would prefer non-sequential notes in small brown envelopes.
David - I'll pay you out of the proceeds of tonights winning ticket, which I thoughtfully bought in town this afternoon!
Cheers,
Number_Cruncher
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Well, I've been using a tank of Asda fuel this week and I'd say that I've been even more careful, striving to hit high 30s on the mpg, but I'm about to run out at 33mpg. Last week I managed 37 on Esso and that included 20 minutes of a high speed run on the motorway. Sure, a sample of one test isn't really enough, hence the need to do mulitple tests so various other factors can be averaged out.
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Well, I know Optimax is no more, but I don't see how it's Octane degrades during distribution.
Optimax is only made at one refinery (at least it was originally), hence it not being available in all areas. Shell made it clear that this was a uniquely high-quality raw fuel and was optimised to need fewer additives and no blending. It was refined to be much nearer to on-spec gasoline (naptha I assume) rather than a mix of low and high fractions and leftovers blended to give something the sum of which equates gasoline. This was supposed to mean fewer aromatics, and fewer deposit-causing low fractions such as paraffins and olefins.
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My fuel buying habits are thus.
Mostly it gets supermarket soup because a supermarket is nearby and is the cheapest. If the chime comes up and says fill up now, if I am not at home, it will get whatever is nearest.
When i first get the car I will try it on a premium priced fuel to see if its any good. If there is no significant benefit to account for the increased price (and usually there isnt) then I dont see any point in paying extra for it.
Special treatment applies before a service. 1000 miles before a service it gets premium fuel, and doses of a specialist cleaner and addative. My feelings are that it cleans out the merde, dumps it in the oil, which then gets changed. I have no idea if thats got any basis in truth, but it makes me feel virtuous.
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TourVanMan TM < Ex RF >
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.....If they ever di dsuch a test it might be interesting to check out the effect of a/c on consumption, an often discussed matter here! .....
This was covered by AutoBild recently, I will try to dig out the issue and put the results up.
Cheers,
Barchettaman
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Thanks B-man - that would be very useful
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Oh dear, I do appear to have disturbed a wasps' nest without ever meaning to do so.
On readintg it again it does appear somewhat sarcastic, but it was based on the text of the thread from tomstickland i.e that a belief is not a substitute for personally gathered tests and also that the author had not spotted the two search faciltiies.
I'm as fallible as anyone else - perhaps due to being able to touch type and sometimes hitting the Enter button without the necessary prethought.
But I've don't have an inferiority complex as far as I'm aware - I've friends who are captains of big industries and others who do equally valuable work at the other end of the scale, but treat them all as equals.
In the meantime I'll get my ruler out to check on whether I've got a small, medium or large one...:-)
My guess is that it's pretty much the same as anyone elses...
- - - - - - - - - - - - - - - - - - - - -
What\'s for you won\'t pass you by
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Oh dear, I do appear to have disturbed a wasps' nest without ever meaning to do so.
Of which I've now tidied up and removed; as well as the comments and replies to your post. You've made your apology, now let that be the last we hear of this please, from all parties concerned.
DD.
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[quote]that a belief is not a substitute for personally gathered tests [/quote]
I'm missing something here? My belief was based on personally gathered tests and the opinion of others. It didn't fall out of the Ether.
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I have found no difference between supermarket and big name 95 ron petrol with ALMOST every car I've owned. The one exception is the renault 19 I used to have (and still would have if the gearbox hadn't died). This ran well on asda fuel, but turned into a bag of doodoo if I used big name petrol. Maybe its because I set the carb up with asda petrol in the tank, I don't know.
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