Supermarket Diesel = Hesitancy/hunting?

[ralph]

My car is a 2010 mk4 mondeo 1.8 TDCI Zetec. I had it for nearly a year and always filled up with standard She'll diesel and it's always been fine.

However my last two fill ups have been at Sainsburys and Asda respectively purely due to convenience and price. Today I have noticed a slight hesitancy/hunting from the engine. This happens if you've been cruising for a while without touching the accelerator (eg going downhill) then you gently touch the accelerator again to resume speed.

Could this be solely down to my car not liking cheaper supermarket fuel? Have I done my engine any long term damage and will it go once I fill up with Shell again????

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[Brycie]

I believe Tesco yesterday admitted to a problem with the fuel at one/some of their stores. Don't know where you're based, but may be worth looking into.

Assuming it isn't the above causing it, I think it isn't likely to be the supermarket fuel causing it after only two tankfuls. The trouble with supermarket fuels is they don't contain many of the detergents that you'll find in Shell, BP, Esso etc. For instance Esso supply Tesco with their fuels, but they don't add the cylinder-top detergent to the stuff they deliver to Tesco, they add it after leaving the refinery when delivering to their own petrol stations only. Over time the lack of detergents can lead to a build up of deposits in the engine, but as I say, I doubt you'd be suffering after only two fill ups.

You could try adding a double shot of diesel additive to your next tankful & see how it reacts after that. If the problem persists after that, I'd advise getting a diagnostic scan done to see if you have a problem with a sensor (eg MAF sensor), or something.

[mixmasterlooney]

Yes this does happen and has happened to me using sainsbury fuel. When getting the gas and revs fall back to idle the revs would fall beyond idle and almost stall, then slight rev hunting for about 3 seconds.

There has been several thread on the forum about this and most would agree supermarket diesel cause problems whilst supermarket petrol is fine. I fill up with Shell and never any problems, I tested this back to back using she'll and sainsbury diesel, at one point I thought I wasn't going to make it home with sainsbury diesel.

Cannot fault Shell at all

[BOF]

However my last two fill ups have been at Sainsburys and Asda respectively purely due to convenience and price. Today I have noticed a slight hesitancy/hunting from the engine. This happens if you've been cruising for a while without touching the accelerator (eg going downhill) then you gently touch the accelerator again to resume speed.

Could this be solely down to my car not liking cheaper supermarket fuel?

Possible. I've always had problems with Asda, but in the sense that mpg readings go down if I use Asda. Now, Asda is always the cheapest, or nearly so, so there is something of a balance, but I won't go for it. To quote the obvious, YMMV.

My approach has been to avoid using supermarket fuel for more than one fill (and by fill, I really usually mean something like a £20 splash, or so, so I rarely have 'pure' Shell, or 'pure' Sainsburys in the tank) in three and to add a splash of Red Ex at every fill.

Have I done my engine any long term damage and will it go once I fill up with Shell again????

It seems unlikely that you have done any long term damage, particularly over that short a period.

Most likely there has been something of a build up of crud and it will go away once you go back to 'decent' fuel and maybe something to help clean up. Maybe, it will take a couple of tankfulls, but it should just clean up.

Having said all that, I haven't had anything to object to about Sains diesel. I avoid using it too much, but I don't have anything concrete to say bad about it.

Normally, I will prefer Shell or Texaco, and use Esso, BP without any real hesitation (BP is cheaper, locally, but I don't really like the company and have had low mpg from their petrol, but not their diesel, so I'm a bit suspicious of them, but don't have anything real against the fuel).

Total I don't have much to say about, either positive or negative, because they are usually expensive where I am, so I don't often buy it (I'd clearly prefer it above Asda, though). Gulf have only recently opened a reasonably priced station locally, so I will try them sometime.

I think I've seen both Esso and Total claiming that the chief advantage of their premium diesel fuels is that you get extra detergent additives, and, for that money, I'd expect a bit more than that (like lower biofuel, or more cetane, or lower sulphur, or something; I'm not sure exactly what I expect, but at the on-cost of premium diesel, it is a bit more; at one or two pence per litre, it would be different).

BP and Shell premium fuels have a good reputation - I'm not convinced there is enough in the fuel economy, particularly against a splash of Red Ex, but maybe I'll do a proper comparison, sometime. Maybe, the added smoothness is real and not just psychological, and that would be worth something, too.

Edit: I also tend to avoid stations with a low turnover of fuel. You sometimes see fuel from car tanks that looks more like 'village pond, recently stirred' rather than 'hydrocarbons, refined' and that seems more likely when it hangs around in the tanks for a long time.

This is a relatively easy thing to do, as the ones with a low turnover tend to be the expensive ones, and the cheaper ones tend to be high turnover.

Edited September 23, 2014 by BOF

[mixmasterlooney]

I cannot vouch for Shell premium fuel I don't use it, regular works great. I agree on the mpg drop with sainsbury fuel and BP fuel although I always think that should be expected

[SeanW]

I'm a petrol car driver, but did have problems with Asda, Morrisons and Esso. I stick to Shell these days. I worked out that the extra 2ppl is almost entirely offset by the improved mpg (Shell Fuel Saver - not V-power). The few pence extra a year is worth it for a happier engine.

[ralph]

Thanks everyone. I had a longish run today (130 miles) and it felt much better on way home. Someone has suggested putting in a tank of Shell V-Power every 2-3 full ups and in between use standard Shell diesel..... Might treat it to a tank of "V" next fill up to purge the cheaper stuff????

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[Brycie]

That's a good idea & something I do myself (though not as regularly as every 2-3 fill ups). I'd still invest in a bottle of diesel additive & give it a double-shot to give it a really good clean to start with. Premium diesels & fuel additives are a much debated issue, some say it's a rip off snake oil, but I believe for a few extra quid per tank, it's a worthwhile gamble for the sake of keeping a three figure engine running well for longer.

Good luck with the issue, hope it continues to improve.

[jeebowhite]

Must admit, I did a splash and dash yesterday with Sainsburys.... The feeling was aweful!

Got back in the car, started driving, it felt like the accelerator was dead, it was slow and unresponsive, the revs where higher and idle and it felt the worst the car had felt in a long time.

I had to do it though, couldnt have got anywhere else, but it just reminds me why Shell is the only fuel I will buy.

[ralph]

Shell it is from now on!! .....Incidentally on ax weeks holiday in France back in August I did two fill ups at the local "Carrefour" supermarket... Very cheap and absolutely no problems!

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[jeebowhite]

yeah its just our skinflint country, where we water down the petrol in supermarkets to just make it that bit cheaper.

They dont charge you for rocks in your scotch, so why charge you for it in the fuel!

[Brycie]

Remember Morrisons B30 fuel or whatever it was called, with a ridiculously high bio-ethanol count?

Problem with supermarkets is imo, getting people onto their land using fuel price as an incentive, is their goal - just so people will do their shopping there. They know 90% of their customers think fuel is fuel & they don't care what it says on the pump. It's just an add-on, or selling tool to Mr Tesco or Sainsburys. With the Shell's & BP's etc, their fuel IS their reputation. If they get it wrong, they have problems. Mind you, with supermarkets creating price wars, even Shell is having to rely on it's shop products to boost profits. Based on the price of their sandwiches, they must be doing very well too!

Weirdly, I hear Tesco Supreme petrol has a higher RON than Esso's premium stuff.

[SeanW]

Our Shell has recently had a major refurb (major as in pretty much bulldozed and rebuilt, tanks cleaned and inspected etc etc).

Apparently, it's one the top 3 profitable Shell forecourts in the country!! (Not surprising really, perched just on the A180 as it comes into town)

[mixmasterlooney]

My Shell had the same last year, funny enough my local Shell is the cheapest by far 130.1 per litre diesel.

Shell seems to care about their image it's always extremely clean, workers are well dressed and helpful. In fact I think a shell gas station offers one of the best services of any gas station plus the last two times I filled up £30 and went over 2 pence the guy let me off because I only had an extra 20 pence

[SeanW]

I tend to pay at pump...much easier and quicker (hate getting stuck behind Dippy Dora with her monthly shopping)

It's not the cheapest - not now the supermarkets have started the latest "price war". But I'll stick to Shell!!

[paul_focus]

I run my focus 1.8 petrol on Shell v power nitro fuel a bit more expensive but for the change in engine performance it's well worth it

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[ralph]

Cheers Paul.... All the time or every few tankfulls??

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[paul_focus]

Maby one tank full every 3-4 tanks of standard Shell fuel

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[ralph]

Last dregs of supermarket fuel used up today so have put in a full tank of Shell V-Nitro Diesel. Notice a difference already after a 20 mile run. Quieter and smoother!!

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[jeebowhite]

That's the reason supermarket juice is so cheap :-D run it on shells Base stuff after this and keep an eye on the fuel filter

[SeanW]

The big companies add extra detergents and stuff to their fuel. Supermarkets tend to buy whatever goes cheapest.

One thing that used to amuse me was that fuel in Grimsby used to be 3 or 4ppl more than Doncaster. The fuel tended to come from the same place...the Humber Bank refineries (Conoco Phillips I believe, possibly Lindsey oil Refinery - can't remember which distributes petroleum products for automotive use)

Grimsby is 12 miles from the refineries. Doncaster is 40-odd.

[BOF]

The big companies add extra detergents and stuff to their fuel. Supermarkets tend to buy whatever goes cheapest.

I think all of the big supermarkets went through a campaign, quite some years ago, of saying 'yes, we also use detergent additives'; whether they add as much, the detergents are as good, as well tested, or the quantities are as well controlled are probably good questions, but there will generally be some.

One thing that used to amuse me was that fuel in Grimsby used to be 3 or 4ppl more than Doncaster. The fuel tended to come from the same place...the Humber Bank refineries (Conoco Phillips I believe, possibly Lindsey Oil Refinery - can't remember which distributes petroleum products for automotive use)

Grimsby is 12 miles from the refineries. Doncaster is 40-odd.

The price charged is more about competition than costs. Both, these days have an Asda, which is usually a good sign - don't generally use their fuel, but it is cheap, and the others nearby may well have to maintain low prices in order to compete, so a Shell an Esso or a BP near an Asda is often a good thing, particularly if those fuel stations are sandwiched between the Asda and another supermarket, such as a Sainsburys or a Morrisons.

[SeanW]

Funny thing is, Scunthorpe sits slap bang in the middle between GY and Donny had fuel prices...exactly slap bang in the middle.

All 3 have broadly similar fuel availability in terms of brands/suppliers. I'm also aware that the supermarkets have to purchase their fuel from the oil companies.

I believe it used to be (used to know someone who worked in sales for Shell)

Sainsburys - Shell

Tesco - BP

Morrisons - Exxon/Esso

Asda - lowest bidder

Much more interesting fueling warships :D

12 knots, 30-50m apart joined by a wire and a hose at a flow rate of 7,500l per minute (450cz/hr)

[ralph]

I'm in Scarborough and it's always expensive compared to inland. Guess we pay extra for hauling it over to the east coast!!!

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[BOF]

I believe it used to be (used to know someone who worked in sales for Shell)

Sainsburys - Shell

Tesco - BP

Morrisons - Exxon/Esso

Asda - lowest bidder

That's interesting. I think (around here, at least) Morrisons changed supplier about five years ago and previously was probably Texaco; back then, using petrol Morrisons was probably one of my most used supermarket suppliers, now, using Diesel, it isn't (although, convenience is also a factor, as I don't drive past them so much).

Also, I think Waitrose used to be BP, but the only one I've been in recently, there were signs that they'd changed to Shell - Waitrose, as you might expect, are rarely super cheap, though.

Going a bit off-topic, there is a station locally that used to be Texaco, became Q8 and is now BP, which still has their air line, etc, with the Texaco branding on it (so, not just the previous brand, the one prior to that); odd!