Murco fuel

Actually I know several people in this area (diesel owners) who refuse to use Tesco for this very reason (smoke and low economy). I don't assert it to be a national phenomena, nor even an absolute local one - I'm simply saying my car - and apparently those of some others I know - absolutely hated Tesco fuel and ran like a dog on it.

I just find the whole thing hilarious actually.

In fact a quick Google search shows up much the same thing. "It's only Tesco diesel I avoid"... "Tesco fuel is very smoky"... "I wouldn't use Tesco unless I really had to."...

This Mondeo thread demonstrates my point nicely:

http://www.fordmondeo.org/forum/printpost.php?tid/795791/

So, a bunch of hearsay from people with no idea? Not really a conclusive point, is it?

Tesco diesel is fine.
 
How on Earth is it so difficult to believe that one brand of fuel can cause a diesel to smoke more than another, or perform differently? This isn't petrol where you get your 95 RON regardless of the pump.

For example, let's say Tesco's diesel meets bare minimum EN 590 spec. That's a minimum cetane index of 46 and a minimum cetane number of 51. BP and Shell on the other hand, have a minimum of 55 and often much more (60 ish). That's going off their own figures. So how in hell do you find it so amusing that one could burn more cleanly and efficiently than the other? This is not petrol. It'd be like you filling up on 70 RON and 95 RON and saying there's nothing in it (cetane is NOT RON, I'm just making a loose analogy).

What's so comical about that? Fox you keep laughing at me and saying Tesco diesel is 'fine' - but how many diesels have you driven, how many diesels do you own, and how much do you know about diesel as a fuel? To say that a fuel with a cetane of 46 is not going to burn any differently from one with a cetane of 55 to 60 is laughable. You can laugh all you like, but tbh it just shows your ignorance of diesel fuel in general.

The fact the net is literally heaving with people who happened to have found the same as me (Tesco diesel - NOT just 'supermarket diesel' but TESCO diesel) smokes where no other does, and burns less efficiently, might 'just be a coincidence' but I don't think so.

But if it makes you feel any better, I am wrong - along with everyone else who has owned diesels for years and found that Tesco diesel smokes more, and gives less power/economy than Shell/BP. You are right; diesel is just like petrol, it's the same 95 RON no matter where you buy it.

:o

EDIT: Oh and regarding why ALL cars filling up at Tesco don't smoke... Most diesels these days (actually pretty much all) are obliged to be fitted with a diesel particulate filter (DPF) by law. This is to meet Euro V emissions regulations. As such the fuel can smoke its **** off but the exhaust will be as clean as a whistle. You won't know the difference until you're faced with an £800+ bill for a new DPF. My last car didn't have a DPF and I can assure you Tesco diesel smokes like a bitch.
 
Good. So you can stop resorting to simple ad homien (LOLOLOL isn't a rebuttal it's an insult) and explain to me how I'm incorrect. Explain to me how a cetane in the 40s doesn't provide a different burn characteristic to one in the high 50s. Explain how EN 590 is a bare minimum required to make the thing go, and is entirely different to the bog standard "95 RON" that is standard across all normal undleaded pumps.

Also explain how biodiesel, for example, has a cetane on average TWO points higher than bog standard EN fuel yet makes the car "surge" due to the extra power, yet you can't believe that Tesco's EN (40-odd) fuel isn't any less powerful or clean than BP or Shell's 55-60 cetane fuel (that's a lot bigger jump than two numbers).

I await your cogent argument to show me how I'm "LOL" for stating that one diesel fuel can burn more smoky and less efficiently than another. That, or your retraction.
 
Rainmaker - without LOL'ing too much, how do you think the exchange supply fuel distribution network works throughout the UK?
 
Rainmaker - without LOL'ing too much, how do you think the exchange supply fuel distribution network works throughout the UK?

I can only guess that you're alluding to the likes of Vopac and the fact that fuel companies 'share' distribution so all Scottish fuel comes from BP, fuel in the North West originates from Shell and so on?

That doesn't answer anything though, because if I sell plain sponge cake (bare EN spec diesel) to Tesco and they resell my plain sponge, and then I (Shell/BP etc) add cream, jam and icing to my cakes before selling them, it's a straw man to say that "they both sell cake from the same place".

Cetane enhancers, lubricity agents, detergents and so on make a large difference. Two cetane numbers makes a massive difference, but Shell actually add to the base stock (which Tesco resell) to take it from ~50 cetane to almost 60 cetane. BIG difference. Yes it's still "cake" and it was from the same place, but it's very different as an end product.

Or did I miss your point? :) I'm still waiting for Fox to tell me how LOLworthy I am for apparently misunderstanding the burn characteristics of higher cetane fuel derived from the same base stock.
 
One thing I can say about Sainsbury's diesel is that it makes the DPF on my girlfriends car regenerate more often compared to Shell diesel. First fill up I noticed it had regenerated twice in a tank full of diesel, the second fill up was followed by the one and only time it came up on the dash to take it for a steady drive to clear the DPF. Started using Shell diesel again and back to approx one regen a tank and no DPF light it didn't however affect the fuel consumption.
 
One thing I can say about Sainsbury's diesel is that it makes the DPF on my girlfriends car regenerate more often compared to Shell diesel. First fill up I noticed it had regenerated twice in a tank full of diesel, the second fill up was followed by the one and only time it came up on the dash to take it for a steady drive to clear the DPF. Started using Shell diesel again and back to approx one regen a tank and no DPF light it didn't however affect the fuel consumption.

My point exactly; some fuel produces more soot and carbon waste than others (i.e. it's smokier and 'dirtier') depending on the base stock and the additives. Apparently though if we listen to Fox all you need in reply is LOLOLOL because that doesn't happen - diesel is diesel remember?
 
Whilst your ability to talk endlessly about Cetane ratings is impressive (That or you paid attention in the research skills module at Uni), your attempt to try and confuse the issue with science is a poor one. It's quite amusing to watch you making constant posts about how excited you are waiting for my reply as if you are a dog with a new bone, or, more accurately, a guy with some newly aquired scientific claims ;)

The point is that you claim that in your Citroen Berlingo diesel, using Tesco diesel fuel results in poor running and visable smoking from the car. It is this claim which I contest is rubbish. You drive probably one of the least powerful, least 'advanced' (I use that word carefully as the HDi is still a commonrail engine, after all) diesel engines produced in the last 10 years.

If Tesco diesel isn't even good enough to power your 90bhp Berlingo without it feeling noticeably down on power and visibly smoking, then it would be logical to assume that the more complicated and more powerful diesel engines fitted to literally millions of cars on our road would have no chance. Yet every Tesco Forecourt is full of people filling up all manner of diesel powered cars without any issue at all and the forecourts are not surrounded by a foggy plume of smug from the apparently terrible unfit for purpose diesel fuel you claim Tesco sell to the public.

It is of course entirely reasonable that different fuels can provide different amount of power in a cars engine. Heck I'd be a hypocrite myself if I didnt accept this given I use higher octane unleaded fuel in my own car for this very reason. But conventional diesel fuel should not in isolation cause rough running and plumes of smoke from your car. If it does, then something is wrong with the car.

Tesco diesel is perfectly safe in your average diesel car and the old wives tales would be best ignored.

As for LOLOLOLOL, it was all I saw fit to reply with given your original claim. I still think its pretty apt.
 
I honestly don't know what to say any more, as you can only come back questioning my 'confusing scientific claims' and my 'rubbish claim' and my 'least powerful least advanced' engine.

This is not petrol. How many times? If you try to put 95 RON in an imported super car it would (as you alluded) run like crap. But 95 RON suits 'normal' petrols just fine and all 'normal' unleaded IS 95 RON.

Diesel is not petrol. There is no standard 'RON' - they all react and burn differently. How is this confusing the matter? It's the CRUX of the matter! YOU might be confused, but anyone who knows the first things about diesel and its fuel isn't.

What's my 'least powerful, least advanced' engine got to do with it? Diesel was known as 'dirty diesel' for a long time before direct injection and common rail were invented. That's because diesel is, shock horror, a sooty fuel. Modern advances have curbed this greatly, but throwing in 'less advanced' fuel can and will produce more soot. That's exactly what Dangerous Dave was explaining above, but you've chosen to ignore him (and all the others saying the same thing as me) as old wives spouting rubbish.

You state that your own BMW won't run as well on 95 RON as it does on super unleaded, but then you try to carry across the analogy to diesel engines ("It's a crap less advanced engine, so it won't matter what you run it on")... It doesn't work like that! Just because a diesel engine is more or less advanced than another diesel engine, it doesn't mean it needs poorer or better quality fuel. Diesel is diesel is diesel in that regard. Better quality fuel will run better in a diesel regardless of its pedigree.

Ever seen a bus or train accelerating? By your argument their "low quality, rubbish, least advanced" type old fashioned engines shouldn't smoke because they're not high end enough to be affected by fuel quality. Clearly that's nonsense.

So as I said, stop trying to make me look silly with my 'research skills module' and my 'silly claims'. Instead, reply (omiting me completely) and explain to Motors who diesel engines work, why cetane isn't (in your words) important, and why a 'low end' engine can't produce smoke on a different fuel.

You don't need to refer to me, you don't need to ask me more questions. Just explain to us why I'm wrong - not just that I am. Back up your answers, and I may just be swayed by your argument.

As it stands, you've done none of these things. You've simply insulted me, demonstrated that you don't really grasp the difference between petrols and diesels (high end petrols needing higher RON does NOT transpose to "low end" diesel engines in the way you suggest), and haven't provided any response that suggests WHY I'm supposed to be wrong aside from "Fox said it is so".

I'm not a dog with a new toy, I'm a guy who is being told how wrong he is over and over, despite his personal experience in the matter, by someone who can't seem to explain WHY he's wrong.
 
You win, I am wrong. Tesco fuel is unfit for purpose and makes everyone's engines bog down and release clouds of smoke. It's really poor fuel.
 
[TW]Fox;17646663 said:
You win, I am wrong. Tesco fuel is unfit for purpose and makes everyone's engines bog down and release clouds of smoke. It's really poor fuel.

No need to be fatuous. Instead, don't give up 'arguing' - debate instead. You've written a load of words in your last two posts, yet not one of them actually provides a real position to refute my assertions. They're just veiled insults, ramblings about my ability to research and talk about cetane ratings (which are much more important to a diesel fuel than is RON in a petrol) etc. You'd make a great politician - answer the questions instead of chatting about slightly related but non-relevant stuff.

As I suggested in my last post, please tell me WHY you are transposing the characteristics of a high end petrol engine (higher RON requirement) onto the lower-end diesel engine segment. Then explain why diesels apparently burn (and have similar requirements to) higher end petrol engines.

Diesels and petrols are, in a way, the opposite way around. High end petrols are sensitive to lower-RON and lower-quality fuel. They need higher RON (eg 99RON) fuel to run nicely and will suffer if you put the bad stuff in.

Conversely with diesel, as I've said, a higher end more modern engine will cope with 'worse' fuel over the short term because the DPF will filter the soot from the smoke (making it look 'clean' regardless) and the ECU will make adjustments to try to get the best from it. You won't know the difference until your sensors all break and your injectors (or worse still the IP) block up before their time.

A low end engine (like my 'less advanced' HDi, or a bus engine) will simply go "eurgh, rubbish fuel... *smoke, smoke*" and run less well. You are constantly trying to admonish my position by comparing petrols to diesels, when it doesn't work. You have your argument back to front. Instead, please just forget my 'claims' and just explain to us why you are right - not just that "you are".

Maybe I'll learn something about the way diesel fuel works and combusts. BTW, don't forget to CC in Shell and BP et al. They're under the misguided impression that cleaner fuel with a higher cetane burns better than base spec EN stuff. They must know that Fox has made a breakthrough, and that everyone is wrong! :p

I never said that Tesco fuel "knocks" or "runs lumpy" - you're putting misquotes into my mouth to make your position look stronger. Again.

I said it smokes more, and delivers less power and less MPG. Given that even the EN spec itself provides a massive allowance for differences in fuel more smoke and less power (lower density, less calorific value, lower cetane) is possible before you even go HIGHER than EN spec in your fuel (eg VPower).

But alas, I'm wrong. Do elaborate.
 
But alas, I'm wrong. Do elaborate.

You are going way, way, too deeply into this.

Different fuels will obviously affect the way a car runs but you are basically suggesting a normal diesel car will not run properly on normal Tesco diesel fuel. It is this which I take issue with.

If we were arguing whether better diesel means you get 2-3mpg more or smoother response then fair enough. But you are basically one step away from claiming Tesco makes your Berlingo HDI undriveable. I mean seriously, you tell us that filling up with Tesco fuel results in a plume of smoke and more than 20% less fuel economy. Thats not just a less suited fuel, that sounds like a downright faulty fuel to me. If you are right, Tesco should be taken to task for selling unsuitable fuel.

I suspect, however, that you are not right. You've correctly identified that certain characterstics in fuels have certain effects, multiplied this 10 fold, and are now convinced that using Tesco fuel in a Berlingo makes it smoke like an HST on full takeoff.

Tesco diesel is entirely suitable for normal diesel cars.

It's not BP and Shell I need to CC into this debate, it's Trading Standards you need to CC if you beleive your claims to be true.

Remember - you are not claiming that BP and Shell fuel is a bit better, you are claiming that Tesco is dangerously poor!
 
Wow, will have to tell my dad about this, MPG going from in the 30s to 50MPG is amazing!

Wow, way to misquote me and add absolutely nothing to the debate. I'm amazed at your knowledge of fuels and the incisiveness in which you destroyed my position.

[TW]Fox;17646829 said:
You are going way, way, too deeply into this.

Different fuels will obviously affect the way a car runs but you are basically suggesting a normal diesel car will not run properly on normal Tesco diesel fuel. It is this which I take issue with.

No, you're now agreeing with me without trying to say it out loud. Originally you were calling me stupid and LOLOL-ing at my suggestion that a car would run differently (not badly, DIFFERENTLY) on Tesco diesel compared to BP and Shell.

All I've ever said is that (1) Tesco diesel runs, but it runs smokier and (2) it returns less MPG (3-5mpg if you actually read what I wrote). This is easily verifiable even by reading the EN spec for diesel. Even if we ignore 'above spec' fuels (VPower, Ultimate) the spec itself provides a massive leeway for fuel quality ("up to" x parts per million water, "at least" x cetane etc).

All I've been saying, all along, is that Tesco is BOG STANDARD. I never, ever said SUB standard - you put those words in my mouth for me and I've been refuting it ever since. I then said that given Tesco is clearly 'bog standard' I have indeed found (as one would expect) that an 'ABOVE standard' fuel works better, doesn't smoke as badly and returns better economy.

Looking at the allowed calorific density within spec, this is easily and quickly demonstrable to even a primary school child. For example even just within 'bog standard' EN 590 spec fuel you can by law add between 5% and 7% biodiesel. Ignoring differences in biofuel feedstock etc (let's say they're identical for now), 5% to 7% biodiesel gives us almost 50% more biodiesel in Mix B than in Mix A. BOTH are EN spec.

Biodiesel is LOWER density, LOWER calorific value but HIGHER cetane than 'normal' fossil fuel diesel. As such more biodiesel gives LESS MPG and (depending on feedstock) more smoke and more water content (still in EN spec).

Such a fuel will, surprise surprise, smoke more and get less MPG. Something you've laughed at me for asserting throughout this thread.

If we were arguing whether better diesel means you get 2-3mpg more or smoother response then fair enough. But you are basically one step away from claiming Tesco makes your Berlingo HDI undriveable. I mean seriously, you tell us that filling up with Tesco fuel results in a plume of smoke and more than 20% less fuel economy. Thats not just a less suited fuel, that sounds like a downright faulty fuel to me. If you are right, Tesco should be taken to task for selling unsuitable fuel.

I suspect, however, that you are not right. You've correctly identified that certain characterstics in fuels have certain effects, multiplied this 10 fold, and are now convinced that using Tesco fuel in a Berlingo makes it smoke like an HST on full takeoff.

Tesco diesel is entirely suitable for normal diesel cars.

It's not BP and Shell I need to CC into this debate, it's Trading Standards you need to CC if you beleive your claims to be true.

Remember - you are not claiming that BP and Shell fuel is a bit better, you are claiming that Tesco is dangerously poor!
There you go with the misquoting and the straw men. I never said Tesco was substandard, I said it smoked more and had less power (and hence less MPG). I said compared to 'proper' fuels (BP, Shell) it ran **** poor. YOU have made assertions on my behalf which extended the scope of my original statement.

As I've said throughout, I can PROVE my position (and have done so to an extent, even the EN spec and biodiesel explanation above achieves this). You on the other hand have misconstrued me, twisted my words, and tried to make me look stupid.

Now, it seems you're rewording my argument and presenting it as your own. If you have simply misunderstood me, fair play. If you re-read the thread you'll see I've been saying EXACTLY what you've just said in that last post, just in different words. I even provided examples to back myself up. Meanwhile you were comparing petrols to diesel and saying I was a lunatic (basically).

As it transpires, I wasn't wrong at all. I can literally write you a referenced essay to more deeply explain my point but that won't be necessary I'm sure. I'm simply saying that you've taken half of the wrong end of the stick, and made a meal of it. I trust now, you can at least agree that I've clarified my position, explained it well, and that I was in fact correct in what I was saying.
 
I don't think, I know. And I didn't say "over" 50mpg I said on Tesco fuel I regularly got late 30s to early 40s, and on proper stuff (i.e. not Tesco) I got mid 40s TO 50mpg over a week of the same driving. That's a difference of around 5mpg, not at all infeasible in a diesel.

Under the exact same driving conditions I would suggest that it's extremely unlikely. For a a penny or two more per litre the branded fuel additives have improved economy by 12% or more? I'm sure the oil companies would be interested in this miracle.
 
Under the exact same driving conditions I would suggest that it's extremely unlikely. For a a penny or two more per litre the branded fuel additives have improved economy by 12% or more? I'm sure the oil companies would be interested in this miracle.

No, I said over a week of driving. Tesco gets between high 30s and mid 40s (a large range because we're talking about different WEEKS of driving, not the same trip over again again in a lab). Over the same average weeks branded fuels tend to give mid 40s and up to 50mpg. The actual difference is therefore about 3 or 4 mpg comparing like to like. I could have worded that section better originally I agree, but I did clarify it later before all the arguing and loling began.
 
You remind me of somebody else on here. Your story has subtly evolved over the course of this little debate to the point where now it actually sounds half reasonable. 3-5mpg? Yea, I buy that, though 5mpg really is the upper range I'd imagine, 3mpg sounds far more reasonable.

But lets remind ourselves of what you said originally, shall we? What you said to prompt my LOLOLOL response, a response I still stand behind.

I struggled to hit 40mpg a lot of the time on the Tesco stuff

So, you struggled to hit 40mpg. Meaning a lot of the time you were therefore... not hitting 40mpg. So, you say Tesco was yielding what, high 30's? Lets be generous and say 38mpg.

It really was poor and smoked like buggery'

Now you are claiming the fuel is poor and you are implying through your choice of language that the smoke from the car was excessive. Sounds bad to me...

Murco stuff returned no less than 45mpg and often 50mpg

Right. So we've gone from struggling to hit 40mpg to now hitting 50mpg. Thats not 3-5mpg is it? Thats 10+ mpg difference.

A return to Tesco fuel has always dropped the mpg to the high 30's

Confirmation again of a potential difference over over 10mpg. Yet here you are now claiming its really 3-5mpg and trying to make out how harsh I'm being for suggesting you thought Tesco was a substandard road fuel causing significant smoking and huge economy differences. Which, as we can see above, is EXACTLY what you claimed.
 
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