Diesel

[iestyn1]

Just bought some cheap diesel from Asda (6p a litre cheaper than my local Shell garage) and I'm wondering if it's of the same quality. I know the mileage I get from Shell and it will be interesting to see if there is any difference. What
are other people's experience?

 

[otherclive]

I never buy supermarket fuel except in France when its sometimes difficult to buy branded fuels. What you never see are the supermarket specs other than meets BS etc. Whereas branded fuels do publish the specs. I tend to use branded fuels and about each 3-4 fill ups put premium diesel into the XC70 as it has lower ash content and a better detergent package and the lubs aid the fuel pump injectors. When towing its Ultimate, Excellium or V power or Texaco's equivalent. Some may say this is black magic but there is sufficient evidence published on the web to show the premium diesels are of higher quality viz ASME/SAE papers, but what they dont support is any significant claims for higher power or anything other than marginal improvements in mpg.

Some will tell you that the tankers all come from the same refinery Thats true but premium fuels are refined differently to standard fuels, and again if you read on the web the additive packages can be added at different stages in the process. So yes they do all leave by the same gate but that's not to say the fuel is the same.
Be interested to hear what your views are after using a few tankfuls of Sainsburys best.

 

[Dustydog]

For six years I used "very little helps " diesel. According to my dealer it was the cause of heavy black smoke caused by the poor fuel gumming up the EGR and turbo intercooler pipes.
Now I use the main brands every other fill and also add either redex or comma diesel addiitives every so often.
No amount of research has proven whether or not the supermarket fuels are substandard.

Arguably all modern diesels should be capable of running trouble free on the lower grade diesel but who really knows??

 

[Parksy]

I run an older vehicle on which the diesel engine probably is less refined than on later models.
I change the engine oil and filters regularly and the engine gives trouble free motoring and has done for years. There is a Tesco and an Asda superstore both within a mile of where I live and I always fill up at one or the other of them. Very occasionally I top up with more expensive fuel if I'm away with the caravan somewhere were there are no large supermarkets, but as far as I can tell there is no difference in performance or mpg, which would be affected more by lack of maintenance than by the brand of fuel used.
If a premium fuel offered better mpg any saving would be lost after I'd driven further to use the premium pump when I'm at home.

 

[ProfJohnL]

I cannot claim any specific knowledge on the content of supermarket fuels vs branded, but having just changed my car and read the manufacturers hand book it appears that whilst Diesel purchased within the EU it should always meet EN 590:2009 standards (BS EN 590:2009 official UK standards for diesel) there are some variations in the additives brand by brand.

All suppliers use additives, so it is of course possible that some may affect engine performance differently.

Purely as a subjective assessment I found in my last car that I perceived the car did seem rougher on Tesco diesel fuel but better on others, but that could just be wishful thinking. I certainly didn't note any significant change in MPG or performance between supermarket and branded super fuels.

I did try Bio diesel on one occasion, but there was a distinct lack of power, and my new car handbook tells me to avoid it However it does seem that a percentage of Bio diesel is already included in Diesel fuels, perhaps this might be associated with different performance.

 

[Mel]

What you need is a "blind" testing. Get your OH (or a.n.other) to fill the car up at either a supermarket or a premium pump for 3 consecutive fill ups for each venue, but not tell you which one they went to. Compare mpg and rate performance. Then ask in which order the car was filled up.
I can do science, me.
mel

 

[xtrailman]

Only use supermarket fuel, ever since it was available.
Not had any engine problems, do local short trips with a PDF diesel, not had a problem.
Car runs great good performace, around 40mpg.
Why would i want to pay more for the same result?
Oh and i never use additives, why would i?

 

[JohnM20]

Many years ago when I was still in short trousers my dad, who was a vehicle mechanic in REME, told me that diesel engines run better when there is high humidity, particularly if it is raining. He went further saying that trials had also been carried out (somewhere) to inject water directly into the engine in a controlled manner to achieve the same result. I've never heard of anything since my dad's comments but I do find, or at least I think I do, that my car does run a little better on a wet day. Is this imagination or is it fact? No doubt someone will have the answer.

 

[RodOne1]

I seem to remember a few years ago there was a much publicised fault with some Tesco fuel that caused damage to certain engines. This was a considerable number of years ago, but, at the time it was well documented. I tend to use whatever brand is closest to hand, and I never really notice any difference. Again, this is from years ago, but wasn't a testing made of the benefits of the different types of fuel such as Ultimate etc, and the end result was so fine as to be inconclosive.

 

[NickinFrance]

I've never heard of anything since my dad's comments but I do find, or at least I think I do, that my car does run a little better on a wet day. Is this imagination or is it fact? No doubt someone will have the answer.

Just Google water injectors for cars, lots of systems are available.
Like you, I've often felt my cars run better on wet days, so these systems might not be all snake oil.

 

[SirRogerFFS]

Some years ago There was a company from Banbury that was Bowes Petro Steam injection .Steam injection was nothing new it was used in aicraft during the war. Petro steam injection used to pour steam into to the carb inlet what it reproduced was the performance of the vehicle you were driving to when you were driving at night in the wet.What it didnt do was increase the fuel consumption it reduced the MPG considerably but would nearly fly.Good invention.....No Longer Available.

 

[otherclive]

It's correct that tests on premium diesels showed marginal or no improvement in mpg or power. They did show reduced particulate and ash, but the real benefits seemed to be cleaning properties and lubricity which help maintain fuel system 'health' particularly in the high pressures associated with CRDI systems.

 

[bluepeter1958]

My mate delivers fuel for morrisons and gets the fuel from the same sorce as shell, tesco and asda, so i carnt see there been much difference

 

[otherclive]

If you read my post above you will see that whilst tankers do use the same terminal/refinery the fuels loaded into them can be different brands with different additive packages although the base fuels from the refinery will probably be the same. But base fuel for premium diesel is different to base fuel for ordinary diesel. See Wikipedia for the different refining processes for types of fuel. For some years now the oil majors have been selling their refineries and concentrating on exploration. Production and fuel developments. So when say BP put a new fuel out it can only come from one or more of the UKs limited number of refineries but it will be the additive package probably added into the fuel at the terminal or sometimes the tanker that makes it a BP fuel.

 

[Sproket]

I seem to remember a few years ago there was a much publicised fault with some Tesco fuel that caused damage to certain engines. This was a considerable number of years ago, but, at the time it was well documented.

I this this is what you are on about ......
Supermarkets-face-10m-bad-fuel-bill
Supermarket-chain-stops-petrol-sales

 

[RayS]

Years ago I worked for what was then one of the UK 'Big Three' breweries. We had a number of brand names which sold better in some parts of UK than others, You could hear the locals swear by 'their' supposedly local brew.
In fact it was all one basic bitter into which additives in the form of more sugal, caramel etc, were blendedon-line immediately before the kegs were filled - all in the same brewery near the geographical centre of the country. Exactly the same control systems were used to blend addatives into road fuel at the point of despatch from the refineries. The tanker drivers would not have been aware of the process.
Someone with a better mrmorty than I have will explaine why most internal combustion engines including gas turbines run better on 'wet' air than on dry. From memory it's because the moisture increases the bulk density of the air and/or because the moisture - being water - increases the effective amount of oxygen slightly slightly abouve the usual about 20%. I'm sur e the late and very much missed Rob Jax would have gien a definitve answer at the drop of a hat, but perhaps this reply will provoke someone into more detailed research.
Certainly water injection was widely used (even in WW2) to improve the performance of aircraft engines, including that of the Bristol Proteus turbines of the Bristtol Brittania (1960') on routes down through Africa with airfields at fairly high altitude.

 

[otherclive]

If all fuels were the same then other supermarkets and branded outlets should have been affected as well, but they were'nt. Fuel distribution in UK is incredibly complex as the refineries and ports are interconnected by pipelines to storage depots and terminals.In the main tankers fill up at terminals as its too far to the nearest refinery and there is the safety risks. Also the 'local' refinery may not make or be capable of making every fuel type. So the ordinary diesel in tyour local terminal may come via pipeline, or train from Fawley, whilst the premium diesel may come from Milford Haven.

 

[Parksy]

The premium grade diesel will only be wasted on your Paj towcar Clive

 

[otherclive]

I think I have to agree with you on that one Parksy, although she still gets branded fuels. The link below takes you to the compilation videos of my recent Mid Wales greenlane weekend. The Pajero only missed out one section where the ruts were just too deep. But of four Land Rovers one dropped out just before we entered the south end of Strata Florida (said it was too rough), and one got home to Wiltshire at 0200h on Monday after breaking a shock absorber bracket and full electrical failure. So I was rather proud of a 19 year old stock Pajero, annd it was comfy too!
http://www.4x4adventuretours.co.uk/blog.html

 

[Parksy]

It looks like great fun Clive and I should imagine that you were definitely warmer and more comfortable than the guys in the 'tin hut on wheels' LR's. Was your Paj the white swb?

 

[otherclive]

Yes it's the white one with as my daughter says ' hairdressers mirror windows'. It was warm, with AC no need for LR demisting with your sleeve and the door seals keep water out on crossing the river Irfon. My wife says I'm a bit obsessed with it, so much so that selling the XC70 is under active consideration

 

[Parksy]

I love Pajeros and Shoguns Clive, I owned my previous Paj, a K reg swb 2.5TD auto for seven years and it was in excellent condition when I very reluctantly sold it. People on campsites often came to chat because it was such a nice looking car especially for it's year. I hung on to it for months after I bought my next Pajero and I only replaced it with the P reg lwb 2.8TD Fieldmaster auto for the extra interior space to be honest, and I've owned the larger model for almost three years now.
Regular oil (10w40 semi synth in mine) air, fuel and oil filter changes kept the old one and now it's replacement purring along nicely, and I drain and replace as much of the ATF as I can every year so it's pretty clean now. The only downsides for me are the fuel consumption around town (22mpg but probably no worse than any comparable 4x4) and the reluctance of some motor insurance companies to quote for grey imports.
If I can spot a nice clean and tidy UK spec T plate 2.8 lwb Shogun manual with leather and cruise control sometime next year I might just go for it, my P plate motor would still fetch about £1500 - £2000 if we had snow like it is this Easter and almost anyone will insure a Shoggie for very little money.
I don't know if you find with premium fuel (scrabbling to get back on topic

) that you need to use the fuel heater?
I have to give mine three 'clicks' in very cold weather to avoid an embarrassingly papal display of white smoke due to unburnt fuel on start up.
After three fuel heater cycles the Paj starts with no fuss and minimal smoke and will start at the merest touch of the key whatever the weather after the initial start up.

 

[otherclive]

Parksy agree with everything you say and I am amazed at how cheap and available parts are too. Yes in cold weather I heat the glow plugs 2-3 times it was a tip that I read on the POCUK forum. But after the first start of the day it's only one heat cycle thereafter. It will be off to Salisbury Plain today as the van is in dock with an obscure battery draining problem. Would have been a nice Easter too, cold but dry. Such is life but at least the lawns will get a trim!

 

[raccoon]

Hi, I run a Nissan X Trail and they are not the best of cars, but never mind that. I was running it using the Asda deisel. I was getting 38 mpg and a lot of injector knock. I changed to BP for a few tanks and found my mpg went up to 40. The injectors were a lot quieter. I then went back to Asda make and put about 100mlts of two stroke oil into a full tank. This made the injectors quieter again.
My thoughts are that the cheaper the fuel the less aditives are in it and do less cleaning of the engine. Putting two stroke oil in the cheaper fuel costs you more per gallon so why do it, you might as well use the better fuel in the first place.
There is a Shell garage near me and I used their fuel a couple times and the engine never seemed to run right. So I stopped using that fuel. I have since found out that it was closed down for a week or so because they had been selling Bio deisel as normal deisel. Dont know if that was my problem or not but will not be going back there in a hurry.
A bus company up here in Newcastle did have some alterations done to some of their deisel buses which saw them injecting water into the cylinders with the deisel and they were acheiving more mpg. I will try a google search to see if they are still doing it.

Stewart

 

[Raywood]

I ran the last car almost exclusively on supermarket diesel for almost five years. We were staying in Chester with the caravan last year and wanted to fill up to get home. A Shell Station looked cheap and I filled up there. The car seemed to lose power by the time it reached Scotland and the partical filter light started flashing when we were nearly back. I did find the flashing light was a malfunction rather than a genuine problem but I do wonder if that Shell fuel was contaminated or if it was the result of a lot of supermarket fuel over the years. I have always used supermarket fuels on previous cars and had no trouble but do now put the odd tankful of premium fuel in.