supermarket petrol - can anyone answer this?

There are only a few refineries in the UK. *All* motor fuel on sale in the UK comes from those refineries. The only difference between major brands and supermarket fuels is the additives included. Shell will tell you that their additives are superior to BP. BP will tell you the opposite. The supermarkets will tell you that their additives are equal to anything used by the big brands. I've been using supermarket petrol and diesel for over twenty years now and have never suffered any engine problems that could remotely be considered due to fuel.

Kev

Didn't you know supermarket fuel knackers rover 75 fuel pumps :-)

cheers, clive

Some supermarkets buy from a fixed supplier, but most buy by 'fly-purchasing' - i.e. they buy any fuel going cheap from any tanker that may be passing.

This results in a tank of mixed fuels. With basic fuels, such as Jet, this isn't a problem, as all suppliers buy their fuel at one depot (go and watch the tankers pulling out of the depot at Buncefield near Hemel Hempstead - which is a Total depot).

The problem arises when they buy from the big brands, such as Shell, BP and Esso. They all use a different mix of additives, and they obviously end up being a cocktail of additives.

Our experience on the cars is that these additives tend to cause contamination in the fuel system, coating the O2 sensor, and the EGR valve with sticking black goo.

Even the use of a single brand is bad enough, we have loads of issues with cars that use Shell in particular.

Let's look at the economics. Supermarkets don't have to make money on fuel

- all they have to do is break even. Cheap fuel is just an investment to get people into the store to spend money and make a profit.

If anyone could prove that supermarket was crud then they would lose a huuuuge revenue stream almost immediatly as everyone switched to a competing supermarket. Hence they are not going to do anything to jepardise that and there will be sufficient lubricants and detergents etc in the fuel.

It's cheap beacuse they make next to zero profit on it. I don't think it's cheap cos it's crap.

Have you (yet) come across any issues with people using Tesco's 99 octane stuff?

Codswallop.

Do the supermarket chains have special refineries to churn out inferior fuel?

I think not.

The only time I have had bad fuel is at a motorway area in France, and I'm sure that was a one-off.

Park outside any refinery. Look at what goes in and out. You'll find all the stores around that area (Morrison/Asda/Tesco) using it as well as all the other major retailers (BP/Shell/Texaco/Jet)

Not knowingly, no. It's one to keep an eye out for though.

I got my 200SX in 2000 with 79K on the clock, it's now got 138K showing. It ran on Tescos 95 ron unleaded for first 2 years and on Asda's 95 ron unleaded for the last 3 years. There is no deposit on the O2 sensor. I must be doing something different.

What you describe is what happens to cars that never go far enough to get properly warm. Tell them to do at least one trip of a least 20 min steady driving (not stop start city/town) every week. Otherwise put it on the high maintenance schedule, change the oil twice as often. Oh yes that's it - I walk to the village store, town about 3 times a week 5 miles there and back (should cycle this as it takes no longer), 5 days/week work is 11 miles 20 min away with few holds ups, once a month a 240 mile M-way round trip to see family. I do oil changes every 3K miles.

Nearest fuel depot I know of to me is Kingsbury, there are a number of tanks that everyone except Shell/BP use, you will see a wide range of brands queuing at the filling point, Shell and BP share a pair of tanks off to one side of the depot and only Shell/BP tankers fill from those tanks - so it won't be in Asda or Tesco tanks.

All the Tescos round here sell Esso.

That's nice.

Put it into context. I'm working from a pattern of issues that arise on cars, based on a large number of vehicles seen. That is why I input information to this newsgroup, I have a better source of data than those that own a single car, or even a handful.

In a year I will deal with, on average, 30 cars ever day, or about 8000 cars a year. On the brand I deal with, it will be mostly routine servicing and minor faults. However, we do still see problems arising, although most are not manufacture defect, they are caused by many possible influences - fuel quality, driving patterns, driving style etc.

We see perhaps a couple or three a month with an engine management fault. However, and again because of the brand, this does relate to a common problem for us.

You are right that this will be worst on cars that are used on short journeys, but it is not for us to tell owners how to use their car, we can only advise them of the causes of their problems. Most of them are fully aware that short journeys are bad, and often accept that things will suffer because of this.

In a large proportion of the cars that have suffered a fault with either the Lambda sensor, or the EGR valve, they use either Shell fuel or supermarket fuel. One or two have used a mix.

Interesting, both of those are the main culprits for additives in their fuels. It's not to say that they wouldn't sell spare fuel to a supermarket though.

Not directly, but on the local radio one of the Tesco stores had put deisel in the unleaded so, some customers had their cars topped with the wrong fuel, in Tescos defence they did compensate for the repairs and inconvenience.

Jesus... how did they manage that?

I was involved in petrol retailing for nearly 5 years and never heard of that happening.

The message from "Avanti" contains these words:

It'd be hard to see how they might get away with not doing so!

Can I ask, how do you know which cars use which fuel, and if they use it all the time or not?

No offence but you seem to think you have amazing data but aren't telling us all the facts.

You mean it's from the Esso refinery?

Yes there is a difference. a few years ago I had a Golf GTi and found it pinked occasionally. Finally tracked it down: ONLY after filling a low tank with Tesco petrol - no other brand that I tested. Apparently, I'm told, Tesco get a lower price from the refineries by accepting the stuff that 'just barely' meets the spec. - just as some electronics manufacturers send their marginal products to countries where complaining is less likely or replacement costs are lower. Dave

And, knowing how the system works, this was more the fault of the delivery driver than any member of Tesco I suspect!

Kev

All supermarket deliveries are driver controlled, with staff having no input into it at all. However, I always thought there was a system with the hoses that meant you *couldn't* put the wrong fuel in the wrong tank..... I only really dealt with the retail and legal side of things, never with deliveries, so I could well be wrong.