Supermarket V Branded Diesel

[weebrian]

I must admit that I am confused by individual reports on various forums concerning the quality of supermarket diesel as opposed to the branded variety.

I have owned several diesel cars over a considerable number of years including Audi, Hyundai, Ford and my present Verso and have never noticed any difference in performance from one supplier to another.

Has any scientific analysis of this ever been carried out or are we to rely on anecdotal evidence from a relatively small number of owners who have convinced themselves that there is a difference?

No doubt an argument that will go on and on but until someone can provide me with the facts and figures, I for one will continue to buy from the cheapest pump regardless.

[Peterkin]

I put Excellium into my 58 SR the other day (by mistake - I was in a hurry and pulled out the wrong hose). The main difference I noticed was that the engine was less clattery when cold. I guess this is down to the higher ketane rating of the more expensive fuel. No obvious improvement in performance or economy.

I normally put regular service station diesel into it. No supermarket stations nearby.

[dervdave]

until someone can provide me with the facts and figures, I for one will continue to buy from the cheapest pump regardless.

Why should anyone bother to try and convince you ?

If your happy thats all that matters and just think of all those pennys your saving !

[Fisherofmen]

All anecdotal & wishful thinking I suspect.

Like Peterkin I have found no improvement in mpg or performance when using premium diesel - so that's a waste of money!

I usually fill with Shell (filling station nearby) but also use supermarket diesels from time to time: my unanswered question is whether the supermarket diesel has less "cleansing agents" or whatever, and therefore over time will soot up my EGR valve more quickly - this was certainly the advice given by my local Saab main agent when I asked a year or so ago, but perhaps they were simply trying to pass the buck with the repeated EGR problems I was experiencing (before I changed to a Verso!).

Incidentally, I haven't found any evidence of better fuel economy since Shell introduced their "new formula" Fuel-Save diesel either!

[dervdave]

All anecdotal & wishful thinking I suspect.

Like Peterkin I have found no improvement in mpg or performance when using premium diesel - so that's a waste of money!

Haway be realistic, you can hardly expect something costing a couple of pence a litre to give startling results can you ?

The benefits you or subsequent owners might get are from long term use.

And sorry if you cannot work out for yourselves what those `benefits` may be because I can`t be bothered to spell them out. :)

[Fisherofmen]

What do you mean by that comment DervDave? Two not a very constructive postings, to a reasonable query by the op.

The question was "Has any scientific analysis of this ever been carried out or are we to rely on anecdotal evidence" - it's never going to be possible for an individual driver to come to an informed conclusion until we are given independent scientific data based on normal mixed driving over 100,000+ miles.

The fuel companies would like to persuade us that their brand offers worthwhile advantages - how about an independent motoring organisation (do any still exist?) or the Consumers Association setting up long-term double-blind trials (where the drivers wouldn't know whether their tanks were filled with supermarket / branded / premium fuels)?

It's easy for unverifiable claims to be made by fuel companies ("save up to 1p per litre" - what's that, 0.1p ... 0.01p ... or 0.99p)

Do EGR valves soot up more slowly if branded fuels are used?

Until we see any such reports, how can we tell whether there are any benefits from long-term use?

[Cyker]

I haven't noticed much difference between the Shell and Sainsbury's diesel I tend to use.

MPG and power-wise, the difference is as insignificant as the difference between Shell's 'old' diesel and their new 'fuelsave' stuff.

The V-Power diesel however does have a noticeable effect, at least on my Yaris. If I go from a practically empty tank and fill with V-Power, you can literally hear the difference in engine sound.

Good things include smoother running, better power delivery at high-revs, cleaner and more complete burn (Noticeably lower particulates), and supposedly the cleaning agents do good things for the injectors etc.

Bad things include a lower power-per mass (So mpg tends to be lower), noticeably less torque at low revs and, of course, the high cost.

This assumes all things are equal tho'; Round my way, there is another (non-V-Power) Shell garage in the other direction and a Tescos, and those two have a rep for poor quality fuels - Rumor is they don't clean out their tanks often enough so all the crap floating around ends up in their fuel.

[Jamesbelfast]

Rumor is they don't clean out their tanks often enough so all the crap floating around ends up in their fuel.

Again more rumour and heresay. If this was the case then cars that use such fuels would need their fuel filters changed more often. As yet I have seen no evidnece of such.

90% of poor engine running problems are attributable to electrical faults but as soon as an electrical fault causes even the slighest hesitation or under-performance of an engine it seems most people jump to the conclusion it must be a fuel related issue. I base these figures on experience of working in the motor trade for 40 years plus.

Some of the so-called super fuels have either octane or cetane enhancers added. This is likely but not in all case improve ignition and cold starting but not necessarily show an improvement in mpg as most engines are designed to run at a minimum standard quality of fuel.

One thing I do know and it's this. I have lost count of the number of crap mechanics who when faced with a difficult engine running problem are very keen to blame someone else and not wishing to blame either the owner or a named individual will pounce on the old supermarket fuel supply issue. It's a nice easy way of taking a customers money and getting them to go away.:)

[dervdave]

What do you mean by that comment DervDave? Two not a very constructive postings, to a reasonable query by the op.

A cheeky post and nearly didn`t bother replying to you, why should I give any answer to you or try to `convince` the OP and why do my comments have to be `constructive` eh?

You choose to use it or you don`t, either way doesn`t matter to me 1 iota, I`m not employed by a fuel company and not on commission and don`t give a frig about what you put in your cars.

[weebrian]

So I would assume from the previous comments that there hasn't been a scientific look at this and there isn't likely to be unless some independent organisation such as Which is prepared to finance what would probably be an expensive operation.

Never mind. I'll just go on doing what I do now and get my average 47mpg.

[Parts-King]

Well this is not scientific, but one of our guys here has a Father who works at Shell Stanlow, HE says that the Premium brand fuels have far more additives for better cold start and cleaner burning, thats why they are more expensive. No need to add anything extra to these fuels as they burn cleaner

Kingo