[Closed] supermarket diesel, whats wrong with it?

Short journeys can be a nightmare for some diesels as you don't get enough run time for DPF regeneration to happen, then it's a costly repair/replace when it goes.

also, common rail disels do re-circulate fuel and this can have a nasty effect on fuel that's in tank. As you will appreciate most fuel now will contain a portion of biodisel, this may be from virgin sources such as rape, soy, and some palm during summer months, but it will also containe UCOME (used cooking oil). Bio diesel is a bitch when it's heated as it starts to oxidise, once it oxidises it will form particulates in the fuel, these will block filters, they will clog injetors and all manner of aother nasty things happen (fuel pumps too. "Decent" fuel, i.e. those with an additive will also have anti-oxidants present, designed to slow this process down, it will always be uch more common in vehicles that sit idle for weeks/months on end. As well as an anti-oxidant it will also have a metal decativator in it, some metals within the fuel lines once oxidation has set in, will act as a catalyst, speeding up the oxidation process - and then the perpetual cycle commences.

edit - not just meatal in the fuel system, but also from the delivery mechanism (terminals, tankers, pumps etc), these will leech.

In terms of things clogging up is that not more likely to be a function of what kind of driving than the fuel.

Might be something in this? My dad only ever drives 5 miles to the supermarket and back so fills up on supermarket fuel.

If i'm doing long journeys on the motorway, i might only ever be able to find Shell/BP etc. so fill up there.

Probably the journey distance has made the car feel better, but it gets blamed on the fuel?

I've yet to see any evidence supermarket fuel is worse, and certainly no evidence it acutally damages cars.

Fifth gear have done a few tests on the subject
They did a fuel test, testing supermarket against "Posh" fuels using a Golf GTI Edition 35, The Rolling Road they used was the very respected tuner R-Tech.

The fuels where fed directly into the HPFP Lines so no mixing of fuels happend, 4 runs where done for each fuel

Shell VPower (98ron) - 240.9bhp - £1.45/litre
Esso Supreme (97ron) - 240.5bhp - £1.44/litre
BP Ultimate (97ron) - 236.7bhp - £1.47/litre
BP (95ron) - 236.1bhp - £1.39/litre
Asda (95ron) - 235.8bhp - £1.36/litre

Looks like you get more power with the higher octane (no surprise then)

[url= http://singletrackworld.com/forum/topic/the-truth-about-supermarket-petrol ]Also discussed here[/url]

I reckon there's a lot of bollocks being talked in this thread personally. Doubt anyone could tell a difference in a blind test. 🙂

Looks like you get very slightly more power with the higher octane (no surprise then)

FTFY

I'd be surprised if there was any performance difference, it all comes from the same refineries, meets the same BS standard and the supermarkets sell so much, that any issues/differences would be well documented by now.

There is, but I can only speak from personal experience. My old Volvo V70 T5 would return about 25mpg if I was careful from Shell's normal unleaded; if I used supermarket fuel, there was no appreciable drop in performance, but the fuel consumption would sometimes struggle to reach 20mpg. If I then went back to Shell/other forecourt branded fuel, hey presto! consumption figures back to normal. I haven't tried it with my new D5 but then I don't intend to.

Similarly, my old man's Skoda Octavia positively refuses to run on supermarket fuel. It struggles under load and returns typically 20-30% worse fuel economy compared to forecourt fuel.

The Transit introduces a slight misfire at really low fuel levels to remind you fill up. Range when the light is on is further than you think!

I simply don't believe there's any difference between supermarket fuel and filling station fuel. Assuming you're talking about the same octane etc, a buyer places an order with a supplier at the best possible price and organises a tanker to go to the refinery to pick up the fuel and deliver to the pumps. I'm pretty sure refineries don't make a cheaper blend of fuel for supermarkets, it would be a nightmare for them to manufacture and hold the stocks.

so reading back we've got people in the trade with first hand experience saying there's no difference whatsoever between branded fuels and supermarket fuel, indeed it all comes from the same source apart from shell v power, higher octane fuels give better performance figures as advertised, and a few people saying they think branded fuel makes their vehicle run better. there's been evidence cited that in tests all fuels are more or less the same. i think thats put this one to bed for me.
as for the van, its running fine now, it started 1st time this morning...

purely anectodtally but my vans sluggish drives like a tank when the mrs is driving but is okay when i m behind the wheel..
statistically mrs tts also has 0.3 accidents a year over the last twelve years where as i have 0.0 ..
its also a fact that i ll be dead if she reads this.

It struggles under load and returns typically 20-30% worse fuel economy compared to forecourt fuel.

The power of the placebo is strong in this thread

If you want to use forecourt fuel do so but lease dont claim its cheaper to buy more expensive fuel

spchantler - Member
so reading back we've got people in the trade with first hand experience saying there's no difference whatsoever between branded fuels and supermarket fuel, indeed it all comes from the same source apart from shell v power, higher octane fuels give better performance figures as advertised, and a few people saying they think branded fuel makes their vehicle run better. there's been evidence cited that in tests all fuels are more or less the same. i think thats put this one to bed for me.
as for the van, its running fine now, it started 1st time this morning...

no we also have some industry experts 8) who says there are differnces, but it's complicated.

and by complicated you mean marginal 😉

perhaps one piston refuses to work on supermarket fuel as its better than that ?

The power of the placebo is strong in this thread

If you want to use forecourt fuel do so but lease dont claim its cheaper to buy more expensive fuel

What can't speak can't lie.

Fill it with supermarket diseasel - it coughs and splutters, won't pull and returns 45 - 50mpg

Fill it with ordinary Shell diesel - it runs fine and returns up to 60mpg.

10 gallons of supermarket fuel costs £63.64p and gives him 500 miles tops = 12.73p per mile.

10 gallons of Shell costs £64.96p and will give him about 600 miles = 10.83p per mile.

So yes, you're quite right - it does make more sense for him to buy supermarket fuel and I'm just telling fibs. 🙄

500 miles

Cant comment on mpg but filling up generally costs about the same from Asda or Shell but there are significant differences in miles before empty with the onboard computer. Generally look at a difference of 80 - 100 miles more using Shell than Asda diesel and generally across the board with other supermarket fuels. Fill up with 65 litres every 6 days from Shell every 5 days with Asda.

you're quite right - it does make more sense for him to buy supermarket fuel and I'm just telling fibs.

can i see your peer reviewed data etc ?

Anecdote, no matter how passionately delivered is not evidence.

Too many factors etc
Its not outlandish to suggest that the driver gives it more revs as they are under the belief they have 20-30 % less power and therefore got fewer miles
As i said there is no independent reviews that i am aware of that cover this issue

According to the Petrol Retailers Association, there is no difference between the standard petrol you buy from supermarkets or franchised petrol stations. In most cases the petrol and diesel is even produced at the same refinery and delivered in the same trucks.

The exception to this is specialist fuels, such as Shell’s Optimax and BP’s Ultimate. In their case, the fuel is enhanced with additives, which produce that brand’s particular properties.

See also
http://www.thisismoney.co.uk/money/cars/article-1642366/Super-fuels-a-waste-of-cash-for-most-cars.html

The standard fuels we tested were all up to the job, wheter from a major fuel brand or a supermarket.
'There's no conclusive evidence to show that super fuels are better for your car in the long run – so in a time of high oil prices, why would you choose to pay more?'

flounce alert

Shouldn't be glow plugs at 60k. Try chucking a tub of injector cleaner through it, change the fuel filter, and at risk of upsetting certain other forum members (cue full-on STW cock-fight) use forecourt fuel instead of supermarket...

Oh and then go and cane the tits off it to clear the DPF out.

risk of upsetting certain other forum members

Seems like there's only one person getting upset.....

I power my hi-fi from a stand alone generator to avoid introducing mains noise, but I can clearly hear that the sound is less authentic when running on Tesco diesel.

🙂

Kcr - bravo! You have summed up the whole of stw in a single post! 🙂

It struggles under load and returns typically 20-30% worse fuel economy compared to forecourt fuel.

perhaps one piston refuses to work on supermarket fuel as its better than that ?

The power of the placebo is strong in this thread

If you want to use forecourt fuel do so but lease dont claim its cheaper to buy more expensive fuel

As I mentioned previously.. VW 2.0 FSI engines can use the 98ron and has the capability in the ECU to adjust timings based on the higher octane number, meaning the fuel can be compressed more before detonating, it also allows the engine to run stratified for longer.

that said. the FSI had tons of problems with people sticking cheap fuel in them and having all sorts of issues.. and thats why VW stopped the FSI engine (turbo is continued)

Not all engines benefit from the higher octane.. but the ones that do will result in better performance and mileage.

My Focus 2.0l is largely responsible for climate change. My wife gets about 27mpg on Tesco petrol (95) and 30mpg on Jet petrol.

Do you remember when cars (mainly French) were conking out and supermarket fuel was to blame? At the time it was reported that supermarkets were buying fuel that was refined in Russia. The supermarkets denied it and said their fuel came from same UK refineries that the other garages used. I don't know where they get their fuel from, but like others, I do see a difference in fuel consumption. We only use Tesco if we've got a 5p off voucher.

snaps - Member

Shell VPower (98ron) - 240.9bhp - £1.45/litre
Asda (95ron) - 235.8bhp - £1.36/litre

Looks like you get more power with the higher octane (no surprise then)

But also that a price increase of about 7% gave a power increase of about 2%. Bargin!

If you are referring to the conking out issue from a few years back, that was down to supermarkets, mainly in the south supplied by greenergy who had bought a shed load of cheap out of spec gasoline, along with some cheap toluene to bring it back into spec. The toluene/styrene had been used as a solvent for washing and was reclaimed, it then polymerised causing polystyrene particles in the fuel.

I sometimes end up doing a lot of miles, and my car runs absolutely fine on supermarket diesel. If I fill up with nice diesel it runs every so slightly smoother. If I use cetane-improved shell V power or BP ultimate etc then it is clearly smoother, and starts better, but any increase in economy is less than the normal variation in economy due to weather, traffic etc. So no more than 1-2mpg.

The price difference between Ultimate and normal seems to still be 6-7p/l, as it has been for years. This was a much bigger percentage 10 years ago, and requires less MPG increase to make it cost effective. However I'm now driving a 60mpg car so I need more MPGs as well 🙂

I have just started using bp fuel and noticed a big improvement in performance and fuel economy compared to Morrisons fuel,after a recent service, and just out of interest, I cut through the fuel filter and it was full of black rubber like particles inside.. 😯

I obviously bought from the wrong place at the start of last winter (but couldn't remember where I'd last filled up a couple of months earlier). The diesel wouldn't start on a cold morning at altitude and there was no smell of diesl or white cloud: waxed diesel. Fortunately I'd parked it where it was all downhill and it came back to life once down in the valley.

globalti - Member

I simply don't believe there's any difference between supermarket fuel and filling station fuel. Assuming you're talking about the same octane etc, a buyer places an order with a supplier at the best possible price and organises a tanker to go to the refinery to pick up the fuel and deliver to the pumps. I'm pretty sure refineries don't make a cheaper blend of fuel for supermarkets, it would be a nightmare for them to manufacture and hold the stocks.

Did you read the stuff I bothered to write? I'm not bothered if you did or didn't, but have you really read this thread?

Cheers.

trail_rat - Member

depends if the leak is before or after it becomes high pressure......

we have a transit that when ever its forced to run on tesco diesel (ie no other fuel stations in town and yer low) it will hunt and die and hunt and die and sometimes stall ....

yet on asda/shell/anyone else its absolutely bob on.

you can set your watch by it when you fill it at tesco it will give the symptoms - every time. coincidence maybe but too much for my liking. Ill actively avoid tesco fuel if i can in any of my cars.

My van (2002 Trafic DCI) has a similar aversion to Tesco Diesel, and it caused me a load of Grief with blocked filters and ultimately a replacement Lift pump, HP fuel pump and a full flush of the tank and lines.
Thankfully I avoided replacement of all 4 injectors but the hassle was considerable.

That was one particular Supermarket, but I still have running problems
every time I am caught and have to refuel at Tesco.

All the other supermarket fuels seem fine ? (I fill up at Sainsburys more often than not as its on my way out from home)

V-Power was control fuel when I was at Cosworth Technology, as it was the most consistant. My Ducati ran much better on it and got better mpg too.

Edit: comment deleted.