Normally Mr Sainsbury or Esso as their pricewatch campaign guarantees good value fuel.
Good point about Winter/Summer grade fuel but mileage is normally consistent regardless of season.
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I find that my Passat 130 TDi is much more economical using Rix biodiesel.
The last time I used BP I was very disappointed, and they have even bulldosed my nearest BP station in Burton!
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See my recent post - on the face of it I should be impressed with Shell diesel:
www.honestjohn.co.uk/forum/post/index.htm?f=2&t=21...0
Oz (as was)
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I bought some BP Ultimate or whatever the other day. Pulled into a service station on the M6 near Penrith having had the warning light on for about thirty miles. I pulled up next to a normal-looking diesl pump and I was filling up by the time I realised that the stuff I was putting in was FOURTEEN PENCE more expensive than the normal. It turned out they only had the expensive stuff so I put in ten litres to get me to Lancaster. I doubt it was fourteen pence a litre better. I was wondering though: is it a biodiesel mix?
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still waiting for shell diesel extra to make it down our way.
In the mean time, I repeat the oft -asked question. Is there, once and for all, any objective, scientific evidence that me pulling up at the shell garage (as opposed to tesco) is doing my engine good...?
Frankly I don't trust anecdotal evidence since I think we can all get ourselves hoodwinked into believing our car is running better one day as opposed to another - on one brand rather than another...I'd rather hear what the mechanical gurus have to say.
Splodgeface
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Splodgeface,
Like you I am suspicious of anecdotal evidence on these matters. Also I would not have thought it difficult to run a trial to get the objective, scientific evidence on any mpg improvement. Shell/BP would surely have got the AA or similar to conduct the trial if they were confident of its outcome.
That said some anecdotal evidence!
My brother runs a taxi firm where the majority of drivers obviously run diesels. He runs a Mondeo 1.8 diesel with starship mileage. He carefully monitors his fuel consumption and has compared BP Ultimate with normal BP over several thousand miles. He finds that Ultimate gives approx 4mpg more - 45mpg compared to 41mpg. The additional cost is 18p a gallon(4p a litre) where he buys his fuel. So if you say his fuel costs are approx 9p a mile he calculates that Ultimate is giving him an (effective) 2mpg more.
Obviously the above only applies to his particular car, with his driving style etc and is no substitute for a scientific test.
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Anecdotally speaking!
The best my car ever ran was when it had almost a full tankfull of BP Ultimate Diesel in it from the blue nozzle,........
trouble was it also had 2.4 litres of BP Ultimate Unleaded in it, also from a blue nozzle. DOH!
An experiment I will NOT be repeating however well it ran.
Totally agree with Cardew's first paragraph above.
Now I've got what I think is a sensible suggestion. Every year the Society of Operational Engineers (formerly the Inst of Road Transport Engineers) run a fuel economy day or two.
Mainly focussed on trucks / vans but fleet engineers also run cars. The aim is to test in as controlled an environment as possible various issues as fuel consumption is so vital to fleet costs.
Strikes me that this Shell Optimax, BP Ultimate vs Tescbury's etc etc is the ideal candidate for such a test. Any members of SOE on here? We'd have to provide the vehicles and drivers.
Usually around June at MIRA IIRC.
Any takers? I'm up for it.
FiF
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I recenty filled up with BP Ultimate Diesel when the garage had no ordinary left. This cost me 6 ppl more than normal, however it seems to have improved economy by about 8 mpg.
I normally fill up at shell (shell diesel extra). My car (Mondeo TDCI 130, 21000 miles) has consistently returned about 45mpg since i got it - 55 liters per 540 miles.
With the BP ultimate I reached 610 miles before filling up again with 52 litres.
the last fill was not BP Ultimate and having covered another 400 miles I don't think i will get anywhere near the 600 mark.
Will try the BP Ultimate again and report back.
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Hmmm, bulk gas oil is 20p litre and that includes 5% VAT.
So why are these premium diesels DOUBLE the price before tax?
Same old story, same product, make it appear more sophisticated and people will pay double, whether it is a bottle of shampoo with 2 drips of tea tree oil in it, or a diesel with a few drops of ether or something in it!
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Gas oil and motor fuel are not the same. Gas oil is required to contain no more than 0.2% sulphur (2000ppm) whereas derv is regulated to contain no more than 50 ppm. Other significant differences include cetane number (not specified for gas oil), lubricant content, and detergency. The Shell product being sold near me is a GTL diesel, with a cetane value in the 70's, and no sulphur content. But if you want to believe its all a swindle, carry on.
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I am sceptical about the validity of these anecdotal claims of fuel economy improvements with particular grades of fuel.
For what it is worth, I have recently run a tank of BP Ultimate and noticed no improvement whatsoever. My concern is, as a seasoned mpg enthusiast, I have experimented with all sorts of driving techniques and worked out just what sort of driving styles my Mondeo TDCi delivers best mpg for. It can vary on mixed runs by as much as 8mpg (42 to 50mpg per tank) depending on whether I drive ?normally? or deliberately feather the throttle and drive very non-aggressively. Its got to the point where I can more or less predict what sort of mpg I?ll get over particular runs, and driving in particular ways. However, I?ve never managed to produce any objective evidence that one brand of fuel is any better than another. I nearly always use Shell (standard grade diesel ? special stuff doesn?t seem to feature in our area) but occasionally use Texaco or BP or supermarket fills just to see.
I use Shell on HJ?s advice, but, as I?ve already posted, I really would like to see controlled scientific evidence that one grade is better than another, you know ? car in the lab, controlled conditions etc... It can?t be too difficult to produce ? why doesn?t someone do this? Then I?ll believe the outcome. Simply relying on anecdotal evidence is no good ? drivers might be hoodwinked into thinking they?re achieving better mpg where what has actually changed is their driving style. When you want to do good mpg, its amazing how, subconsciously, your driving style changes ? perhaps this is what is delivering these ?claimed? improvements.
Splodgeface
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I agree. I'll bet the fuel makers compared the 'benefits" but its no doubt under wraps. Pity Evo are not too keen on diesel, but who knows? With a Honda type R diesel rumoured to be on its way, and the sequential twin- turbo Vauxhall and BMW engines, there might be a story in it for them, as well as a bit of fun.
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I've a question concerning BP Ultimate etc. (Hope this is an appropriate place to ask, and that it has not been dealt with elsewhere)
The adverts for this stuff show pictures of nice shiny clean valves from cars that use BP Ultimate beside pictures of rather grubby looking valves from cars which run on ordinary fuels. I have a vague recollection of similar pictures in adverts for some superior petrol, perhaps 10 or 15 years ago. Anyone else remember such pictures / adverts, or is my memory faulty? And if my memory is correct, what exactly is the story? Has the superior petrol of 10 / 15 years ago become the ordinary petrol of today?
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Going back even further than that*, I can remember a Shell Oil presentation in a local hotel where they were demonstrating an allegedly 'totally clean burn' oil on the crown of a heated piston.
* It was so long ago, there was as much whisky as you could drink, courtesy of Shell.
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Tyro, probably cobblers, I run my BMW diesel on cooking oil, the cheapest ULSD I can get, and my valves are clean,, and my injectors tips have a normal soft black deposit on them. So why should I switch? I can't tell the difference between any of the ULSDs but I'm a skeptic these days, before I was a skeptic, I would have found the more expensive ones to be superiot, because i would so much want them to be.
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This is a copy of my post on another forum back in April;
" I've now gone back to my usual Esso as I could detect no difference in noise/performance on my '01 Clio dci (now 26k) from using BP Ultimate. Even using a stopwatch for in-gear acceleration times.
If you suffer from a low boredom threshold, please stop reading now.
Shown below have been my mpg figures for the last half year, with seasonal change perhaps showing more signifigant difference in the mpg than fuel used.
MPG starting from mid Sept 03;
69, 65, 63 - Esso,
62, 62------Shell (not Extra),
New Year
59, 58, 64 - Esso,
63, 58, 60 - BP Ultimate,
67, 67, 72 --Esso.
In that order to present.
I wasn't too happy with Shell as the car seemed to be producing more smoke while using it.
From my experience, I can only say that Ultimate may work for engines with a higher mileage on the clock, or for certain engine manufacturers."
The reason I used it for three fills was to even out the difference caused by using different fuel stations/pumps etc. The fact that it was costing an extra £1.30 a tankful didn't help either!
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Turning the question round a little...
If you were charged with marketing a commodity (fuel, oil, tyres, etc), which has to meet, or exceed British Standards, how would you do it?
Hints;
There are lots of different types of cars
There are differing driving styles
There are differences in maintenance
etc... -----> myriad combinations
So, if you are shrewd, you can make bold claims, because you are very unlikely to be *proved* wrong.
A marketeer's dream. Buyers beware!
number_cruncher
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Article in today\'s Sunday Times - hardly conclusive but may be of interest
(Snip. Sorry, no links to The Sunday Times.)
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Interesting article, and if it's the same Dave Pollard, he used to write some good automotive books, but here is one glaring inaccuracy...
"The basic reasoning as to why the super fuels boost performance is that they have a higher octane rating (they are more explosive). "
Of course a higher octane rating means the fuel is less explosive, and gives a more progressive yet sustained burn.
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As some regulars may know I'm new to this diesel game. So far (3 fill-ups)I've just put in the cheapest I can find - usually 5p off per litre at Tesco or Sainsbury - wherever SWMBO has been shopping.
Some of it is called City Diesel - why?
Reading all the posts above has confused me no end.
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Just to put your mind at rest, Dulwich, some old hands at the diesel game (i.e. me) are also fans of "5p off per litre at Tesco or Sainsbury".
Ian
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Tyro
I ran my old BX TGD for 150k - no matter what fuel I used it always seemed to do the same mpg ie after 400 miles I would fill up with 40 litres give or take a couple.= 45 mpg. About 70% was Sainburys or Tescos, rule was the cheapest I could find. Engine never touched so don't know what condition the valves were in but it never had new injectors. I did however occasionally put a shot or two of Millers in (as HJ recommends?) just before MOT.
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He he,
Italian tune ups are the usual pre MOT prescription for Vauxhall diesels. It is amazing the amount of smoke and soot that you can get out of some!
number_cruncher
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re City diesel: thats the fuel I used most often in my TDI's. Made (or maybe marketed) by an outfit called Greenergy, who have a web site giving details of its cetane and sulphur content etc.
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An intresting article from The Sunday times can be found here -
8< Snip 8< . see Marks message below. DD.
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