RE: Supermarket fuel: is it good enough?
Thursday 1st March 2007
Is Tesco's petrol causing problems? One PHer reckons it's cost him £90 for a new fuel sensor, although Tesco said that it's found no problems with its fuels.
Supermarket fuel: is it good enough?
One PHer reckons it's cost him dearly
Here's the PHer's story:
"I have a Vauxhall Corsa and whilst driving home last night my Exhaust Emissions warning light came on. I rang my local garage this morning and was told I was the third one they'd had with this problem this week and that they had been told by the Vauxhall main dealer that it is being caused by a bad batch of fuel - I last filled up at Tesco in Dereham on Sunday.
"I have now spoken to Hartwells who have confirmed that this is a nationwide problem affecting all makes of cars -- not just Vauxhalls -- and seems to stem primarily from Tesco fuel although they have had some cases involving Asda fuel. They couldn't tell me any more at the moment other than to continue using the car if it is running OK and see what happens the next time I fill up. I am probably going to need a new sensor at £90.00 plus VAT but they don't know whether it will have caused any more permanent damage!"
In response, Tesco issued this statement: "We and our suppliers rigorously test all our fuels to the highest possible standards. We have carried out extensive tests on current and past batches of unleaded fuel to the European EN228 standard and have discovered no abnormalities or contamination whatsoever.
"We source from exactly the same suppliers and our fuel originates from the same depots as many of our competitors, and so if a problem did emerge it could not by definition be Tesco-specific.
"We are aware of a small number of customer concerns regarding this particular issue. While we take matters of product quality very seriously indeed and will continue to monitor the situation, it is unfortunately quite common for mistaken rumours to arise as to the provenance of car maintenance issues."
An Autocar story suggests that the fuel came from a contaminated batch via a distribution terminal in Essex, and that an outbreak of combustion problems appears to centre around petrol stations in the Essex, Hertfordshire, Buckinghamshire and Middlesex areas -- although some reports of problems have come from places far apart, including Fife in Scotland and Dorset in the south.
We'd like to hear from you if you've experienced problems that could be fuel-related.
Discussion
"SUPERMARKET FUEL: IS IT GOOD ENOUGH?" - Jesus, talk about jumping on the media bandwagon. The chances are, if there is a problem, this will be some random manufacturing or transportation fault which could equally have affected any of fuel retailer. Asking the general question that is supermarket fuel somehow proved inferior by this is laughable.
No it's not conspiracy theory. They have switched over to using a small percentage of bio-fuel in supermarket petrol in order to reduce emissions. The bio-fuel is quite expensive (produced from turnips) but is seen as an important part of theitr "green" policies. Small pieces of turnip pass unburnt through the engine and adhere to the oxygen sensor, knocking it out of action. This brings the car to a stop and reduces emissions to zero.
I'm an auto engineer working for a supplier of EMS (Engine Management Systems) to manufacturers, and can see no way that if ethanol was added to the petrol it would damage the oxygen sensor. They are usually messed up by oil contaminates or lead contaminates in the fuel. My guess as to the reason they are changing the sensor is that the EMS is falsely diagnosing a fault with the sensor, as it was never calibrated to see an ethanol fuel.
My first thing to do would be to drain the fuel tank, fill up with a good source of fuel and then clear the fault codes and see what happens. I'd expect everything to be fine.
My first thing to do would be to drain the fuel tank, fill up with a good source of fuel and then clear the fault codes and see what happens. I'd expect everything to be fine.
Trading standards officers are investigating the source of petrol contamination which has apparently caused a spate of car breakdowns.
Garages are struggling to deal with an influx of cars which are feared to have broken down as a result of "contaminated" petrol sold on supermarket forecourts.
Ray Holloway, director of the Petrol Retailers' Association, said even motorists who have not been affected might want to consider dumping the fuel in their tanks.
He said: "Motorists who have not been affected could save themselves a bill by changing the petrol in their tanks. That would be my recommendation."
Drivers said they had experienced problems after buying petrol from Tesco outlets in the south of England, although there were reports it could have spread across the country.
The Society of Motoring Manufacturers (SMMT) stressed the urgency of finding the source of the potential contamination, which was still unclear.
Chief executive Christopher MacGowan said: "It is a very worrying problem. Down to the present moment, the real difficulty is absolutely identifying what has happened."
The petrol has been affecting oxygen sensors, which are part of the engine management system and help the car run smoothly if it is operating normally or help it shut down if there is a problem.
Mr MacGowan said there had been a run on the components in recent days, leaving some drivers with their cars off the road for two to three days because a replacement was not available.
The problem had come "completely out of the blue", he said, adding: "I have been in this industry for many years and I cannot remember a similar occurrence on this scale."
Garages are struggling to deal with an influx of cars which are feared to have broken down as a result of "contaminated" petrol sold on supermarket forecourts.
Ray Holloway, director of the Petrol Retailers' Association, said even motorists who have not been affected might want to consider dumping the fuel in their tanks.
He said: "Motorists who have not been affected could save themselves a bill by changing the petrol in their tanks. That would be my recommendation."
Drivers said they had experienced problems after buying petrol from Tesco outlets in the south of England, although there were reports it could have spread across the country.
The Society of Motoring Manufacturers (SMMT) stressed the urgency of finding the source of the potential contamination, which was still unclear.
Chief executive Christopher MacGowan said: "It is a very worrying problem. Down to the present moment, the real difficulty is absolutely identifying what has happened."
The petrol has been affecting oxygen sensors, which are part of the engine management system and help the car run smoothly if it is operating normally or help it shut down if there is a problem.
Mr MacGowan said there had been a run on the components in recent days, leaving some drivers with their cars off the road for two to three days because a replacement was not available.
The problem had come "completely out of the blue", he said, adding: "I have been in this industry for many years and I cannot remember a similar occurrence on this scale."
You know what? Every time something has gone wrong on one of my cars, I've put fuel in it beforehand. Well, I've visited the petrol station for the last time. No more "filling up" for me, and no more breakdowns either!
Omega has been running ethanol blend for ages without trouble, surely the contaminant has to be something else?
Is there actually a problem with cars breaking down, or that something in the fuel - maybe - is throwing the EMS' of cars?
I filled up with Tesco Super Unleaded in Cambridge on Saturday so am concerned, although would expect that the lack of "systems" on a 35 year old engine would mean that I may just get through th etank even if contaminated, unaware of a problem because my dash doesn't look like Blackpool prom.
To be honest I am not sure about Supermarket fuels - not because its crap or anything, but because its not just the supermarkets that are doing it. I have suffered twice over the years with crap fuel - one from a motorway service station and one from a leading brand outlet in a town. Both times required a trip to the garage / dealer to rectify it and there was little I could do about it.
That said, was there not a chap with a new BMW Z3 coupe who got a tank full of water recently? And from a garage?
Last year I suffered a split fuel tank. Obviously had to be replaced and the amount of crud and crap at the bottom of the tank was shocking! Not just a little bit of sludge but around 1-2 litres of the stuff! Thank god that I dont run my tank down! Ok, so its built up over the years but it just goes to show what we are sold and its not all perfect - in fact far from it.
Would the supermarkets willing sell duff fuel? Due to the potential customer fall-out as a result its a VERY dangerous game. Its a large amount of revenue (I doubt they make money on the fuel) that they run the risk of loosing and brand loyalty is not that strong when it comes to screwing up your car!!!!
That said, was there not a chap with a new BMW Z3 coupe who got a tank full of water recently? And from a garage?
Last year I suffered a split fuel tank. Obviously had to be replaced and the amount of crud and crap at the bottom of the tank was shocking! Not just a little bit of sludge but around 1-2 litres of the stuff! Thank god that I dont run my tank down! Ok, so its built up over the years but it just goes to show what we are sold and its not all perfect - in fact far from it.
Would the supermarkets willing sell duff fuel? Due to the potential customer fall-out as a result its a VERY dangerous game. Its a large amount of revenue (I doubt they make money on the fuel) that they run the risk of loosing and brand loyalty is not that strong when it comes to screwing up your car!!!!
The supermarkets are currently saying 'not us', as are the fuel suppliers. I smell whitewash...and it's not from the builders next door!
Ethanol doesn't sound like the reason...not unless it hadn't been prepared properly. What're the odds of a batch being contaminated with something else (water?)?!?
Ethanol doesn't sound like the reason...not unless it hadn't been prepared properly. What're the odds of a batch being contaminated with something else (water?)?!?
I had to replace an entire fuel system at a personal cost of £2,000.00. I was told by the manufacturer it was down to contaminated fuel, then also told by an independent specialist that it was contaminated fuel.
The car had been exclusively fuelled at one single ASDA self-serve station and we have never been there since.
But because I cannot prove a single thing, then I have had to foot the bill personally. Two grand?!??!??! That could have gone on a big TV!
I can chuckle about it now, but in terms of negative publicity alone, this is catastrophic for the supermarkets. We have 2 cars and they will never EVER be fuelled at supermarkets again.
P~
The car had been exclusively fuelled at one single ASDA self-serve station and we have never been there since.
But because I cannot prove a single thing, then I have had to foot the bill personally. Two grand?!??!??! That could have gone on a big TV!
I can chuckle about it now, but in terms of negative publicity alone, this is catastrophic for the supermarkets. We have 2 cars and they will never EVER be fuelled at supermarkets again.
P~
PhantomPH said:
I had to replace an entire fuel system at a personal cost of £2,000.00. I was told by the manufacturer it was down to contaminated fuel, then also told by an independent specialist that it was contaminated fuel.
The car had been exclusively fuelled at one single ASDA self-serve station and we have never been there since.
But because I cannot prove a single thing, then I have had to foot the bill personally. Two grand?!??!??! That could have gone on a big TV!
I can chuckle about it now, but in terms of negative publicity alone, this is catastrophic for the supermarkets. We have 2 cars and they will never EVER be fuelled at supermarkets again.
P~
The car had been exclusively fuelled at one single ASDA self-serve station and we have never been there since.
But because I cannot prove a single thing, then I have had to foot the bill personally. Two grand?!??!??! That could have gone on a big TV!
I can chuckle about it now, but in terms of negative publicity alone, this is catastrophic for the supermarkets. We have 2 cars and they will never EVER be fuelled at supermarkets again.
P~
I hardly ever did anyway, but like you I'll make a point of sterring clear of them from now on.
The car's been in for servicing this week so my timing may have been very lucky indeed.
Edited by nobleguy on Thursday 1st March 11:39
probably the latest underhand terrorist activity 
...or have these various tanks been spiked with Polonium 210 even.
Joking aside, a few years ago the wifes Mazda had similar fuel probs & local fitter said he had 5/6 owners with same problem all of whom filled up at local Tesco. On stripping & draining fuel system problem turned out to be water in cars' tanks.!
...or have these various tanks been spiked with Polonium 210 even. Joking aside, a few years ago the wifes Mazda had similar fuel probs & local fitter said he had 5/6 owners with same problem all of whom filled up at local Tesco. On stripping & draining fuel system problem turned out to be water in cars' tanks.!
Edited by sprinter885 on Thursday 1st March 11:43
Eddy5 said:
I'm an auto engineer working for a supplier of EMS (Engine Management Systems) to manufacturers, and can see no way that if ethanol was added to the petrol it would damage the oxygen sensor. They are usually messed up by oil contaminates or lead contaminates in the fuel. My guess as to the reason they are changing the sensor is that the EMS is falsely diagnosing a fault with the sensor, as it was never calibrated to see an ethanol fuel.
My first thing to do would be to drain the fuel tank, fill up with a good source of fuel and then clear the fault codes and see what happens. I'd expect everything to be fine.
My first thing to do would be to drain the fuel tank, fill up with a good source of fuel and then clear the fault codes and see what happens. I'd expect everything to be fine.
I agree - as someone else in the industry I'd guess the sensor is seeing an AFR variation outside of it's normal operating range which is flagging a fault and going into limp home mode.
As you say, draining the tank and clearing fault codes, not changing the sensor is probably the solution (aand cheapest).
Ethanol needs to burn around 7:1 rather than petrol 14.7:1 so you need 2x as much. If your injectors dont flow that much it will run like crap. Perhaps the injectors were just maxed out because there was too much ethanol in the mix?
This might show as a o2 sensor issue. If so then it sounds like the garage was more concened about making money out of the customer than working out what the problem acutally was.
This might show as a o2 sensor issue. If so then it sounds like the garage was more concened about making money out of the customer than working out what the problem acutally was.
I would suggest it's specific to particular filling-stations and their individual management. Surely you've noticed that the storage tanks are underground..who knows what crap can get in there to contaminate the fuel?
Does anyone get inside the underground tank to check for leaks and cracks?
Or is the inside of the tank disintegrating, especially older ones?
Of course, I bet the fuel testers get samples straight from the suppliers and not from the pumps.
I've noticed dodgy fuel over the years and their's only one solution, fill up somewhere you know is good!!
Does anyone get inside the underground tank to check for leaks and cracks?
Or is the inside of the tank disintegrating, especially older ones?
Of course, I bet the fuel testers get samples straight from the suppliers and not from the pumps.
I've noticed dodgy fuel over the years and their's only one solution, fill up somewhere you know is good!!
Edited by bri_the_fly on Thursday 1st March 12:04
I avoid supermarket fuels most of the time.
Most fuel comes from the same few suppliers, the only difference is the additives that are put into the tanker depending on whether it is Shell or BP or whatever brand. I have been advised that supermarkets put far less additives in and therefore the fuel does not have the cleaning properties of more expensive brands.
I have in the past spoken to 2 (& heard of more) people that have had sticky valves, stuck to the head of their cars and one of them filled up at 'a supermarket' all the time. The mechanic stated cheap fuel was the problem.
The odd tank will make no difference, i have even done it myself, but my opinion is not to run on the cheap stuff.
My belief in life is that you get what you pay for, hence i buy V-Power (Optimax) and dont shop at Tesco.
Most fuel comes from the same few suppliers, the only difference is the additives that are put into the tanker depending on whether it is Shell or BP or whatever brand. I have been advised that supermarkets put far less additives in and therefore the fuel does not have the cleaning properties of more expensive brands.
I have in the past spoken to 2 (& heard of more) people that have had sticky valves, stuck to the head of their cars and one of them filled up at 'a supermarket' all the time. The mechanic stated cheap fuel was the problem.
The odd tank will make no difference, i have even done it myself, but my opinion is not to run on the cheap stuff.
My belief in life is that you get what you pay for, hence i buy V-Power (Optimax) and dont shop at Tesco.
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