Diesel

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Jon

Diesel

Post by Jon »

Have always run the Zx on Shell Optimax on the grounds that its fairly cheap (74.9p a litre at the local filling station as I write), car runs well and does nor smoke too much.
Now I'm working in Feltham, and leave very early in the morning, I have been using Tesco City Diesel from the Tesco hypermarket in Feltham on the grounds that I get "reward points". Also, the Shall place in Swindon does not open until 7.00am and I'm usually coming out of town about 6.30AM. [|)]
I've noticed over 6 weeks of using the Tesco stuff that economy is slightly down, plus an increase in smoke during acceleration. Running however is very smooth. "Performance" (sic) is about the same as before.
The question is, is there there really any difference between the supermarket brands and the other major brands? Has anyone else noticed this?
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Post by Richard Gallagher »

Yes I have, supermarket diesel fuel does seem to an inferior product compared to Shell in particular. I'm occaisionally given some money off vouchers from a friend for Safeways fuels, but unless its more than 5p a litre off its a false economy due to higher consumption. Honest John in the Telegraph regularly mentions the poor quality of supermarket fuels.
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Post by rossd »

But how do you come to this conclusion? Depending on which part of the country you are in, Tesco is supplied by either BP or Shell. They even have their tankers deliver to the supermarkets around here.
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Post by wrinklet1 »

Hi all, just to put some things right . I work at Tesco and have worked in the petrol station. The fuel that they sell is Texaco and in fact they pay more per litre than Texaco petrol stations. Tesco use all the latest additives in their fuel, this can cause a reduction of economy in higher mileage cars and can also cause a puff of smoke when accelerating. Bearing in mind that Tesco only make 9pence a litre profit, and that they have to pay for everything out of that small mark up. If you go to almost any supermarket you will find that the fuel is just the same as any 'normal' petrol station. In fact, the petrol station at the Tesco I work in turns over £250,000.00 a week, so the fuel is in fact cleaner than most normal stations.
Cheers
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Post by jeremy »

When the supermarkets oiginally went into the fuel business they were buying their fuel on the spot market in places like Holland and then importing it into this country.
As well as refineries the oil companies have a number of facilities for off loading tankers and BP have one at Hamble on Southampton Water. I believe this handles fuel for at least one of the supermarkets and it just because the fuel comes out of the gate of a BP facility doesn't mean that it is BP fuel. It is perfectly possible for them to unload supermarket fuel into separate tanks and the pump it into tankers for distribution and it may even be that non supermarket tankers are used for the distribution.
Having said that I know from working in the food industry that supermarkets can be a bit touchy about the sources of their own brand food products and will insist on collecting in their own trailers rather than having it delivered in manufacturers trailers.
jeremy
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Post by RichardW »

Jon said:
"Have always run the Zx on Shell Optimax on the grounds that its fairly cheap (74.9p a litre at the local filling station as I write), car runs well and does nor smoke too much."
I hope not[8D] - Optimax is high octane petrol - not likely to go down too well in a ZX TD[8D]
I have used Tesco in the past a few times, and not noticed any significant change over a single tank full. However, I did once fill up at Asda in a BX TD - the MPG dropped from 45 to 40 and it smoked like buggery - didn't do that again!
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Post by JohnD »

Nearly all the diesel I use in my Xantia is French, so it's a 5% mix of bio-d. Sometimes it comes from the hypermarket and sometimes from the Elf station, but apart from the 7p per litre difference in the price, I've never detected any difference in performance. Having said that, during the summer I took almost a full tank at a Shell station in Luxembourg (45p per litre), and was amazed at how well it pulled the caravan along the motorway.
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Post by KevMayer »

Whenever I drive my diesel in France I always get the feeling that it runs better on French diesel, especially ELF.
Could it be a higher octain ?
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Post by Kowalski »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by KevMayer</i>

Whenever I drive my diesel in France I always get the feeling that it runs better on French diesel, especially ELF.
Could it be a higher octain ?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
It would have to have a higher cetane and therefore a lower octane but is probably due to the specific energy of the fuel or placebo effects...
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Post by rabenson »

I used to work at a shell oil refinery (teesport) and we used to get all sorts of tankers including most of the supermarkets filling up with diesel and petrol. Its my understanding that the base fuel is the same but that extra additives are put in to "brand" the fuel and that is what varies.
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Post by mrbump »

Just to back up what you guys are saying, I was at a presentation today given by representatives of the BP refinery (in Grangemouth) here in scotland who said that EVERY petrol station in scotland uses their petrol/diesel, and supplies 40% of UK diesel/petrol to rest of UK. So you wouldnt think that there would be any difference?
All of the BP fuel processed at grangemouth is taken from the north sea and is refined on site. None of it comes in on tankers or is re-processed. It all goes through the same quality controls. The only difference in branded/supermarket fuels must occur at the pump stations. Maybe it has something to do with they way they clean the holding tanks, or some detergents getting into the fuel. I must admit that supermarket diesel does seem to produce more smoke.
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Post by KevMayer »

Very interesting Kowalski. Just what I was thinking.
(Aside to audience:- I must admit I haven't got a clue what he is talking about !).
I respect a man who has expert knowledge. So, thanks for your input kowalski. If you have the time though I'd be interested to know what you mean by high cetane means low octane, and what are placebo effects. it is above most of us here i'm sure.
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Post by puddle jumper »

I think french diesel is the "old stuff" that we used to use and not the low sulpher derv or city derv that is in every pump now,I also think french derv has more detergent in it than uk derv. I agree with KevMayer my Xantia runs a lot better on french diesel. I think it has more power - but that could be my wallet talking !
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Post by wrinklet1 »

I get more mpg and more power when I run a mix of 9litres of veg oil to £15 of diesel and a cleaner exhaust too....
Paul
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Post by JohnD »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by puddle jumper</i>

I think french diesel is the "old stuff" that we used to use and not the low sulpher derv or city derv that is in every pump now,
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Not at all! All diesel sold in France is made up from a 5% mix of bio-diesel, which gives it an even lower sulphur content than our own. Citroen/Puegeot engineers claim that their engines will run on up to 30% mix without showing signs of additional wear
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