What do Tesco do to their fuel??

mutley74

GolfBravo wrote: »

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I took the car for a drive this morning and it started the DPF regeneration process almost immediately (rear demister automatically on, radiator fan on, took about 15 minutes in total) and then behaved OK again. The reason why it started the DPF regeneration straight after refuelling (but eventually didn't complete it due to short distances) is very simple: almost all modern diesels will not regenerate the DPF when the low fuel warning light is on. As soon as you add fuel the light goes off and the DPF regeneration process starts almost immediately. So people may associate the DPF regeneration process with refuelling/"bad fuel" - my wife did.

how does operation of the rear demister help your DPF????

For any diesel car long regular journeys of at least 30mins are recommended to clean out the DPF, as it does not reach high enough temperatures on a short temperature.

Ultrasonic

mutley74 wrote: »

how does operation of the rear demister help your DPF????

It increases engine load, I believe increasing the heat generated in the engine and therefore the temperature of the downstream components, including the DPF.

GolfBravo

mutley74 wrote: »

how does operation of the rear demister help your DPF????

The car's ECU puts on the rear demister (and in really urgent cases also the radiator fans) to put as much load on the engine as possible - the aim is to quickly increase the exhaust temperature to regenerate the DPF. The demister light stays off though.

Iceweasel

cardinalbiggles wrote: »

In the case of Grangemouth both Shell and BP tankers come out of there all day long I can assure you of that.

I am actually well aware of that cardinal biggles, but I see that my post was not clear.

I asked where Shell and BP were as owners of refineries, as they are the names that everyone knows 'produce' petrol and diesel.

They of course are not there as Shell and BP do not actually refine any products in the UK any more - they are just like Tesco - retailers of fuel they purchase from Greenergy.

The popular conception (ask anyone in the local pub - they know everything) is that Shell & BP actually run the whole show independently themselves from exploration right through to selling 'their' product.

In reality 'their' product is no different from any other filling station's - just with a few more 'herbs and spices', sorry additives, to make it a bit different.

Jamie_Carter

cardinalbiggles wrote: »

In the case of Grangemouth both Shell and BP tankers come out of there all day long I can assure you of that.

It'd operated by Petrolneos, who will sell/provide a service to many oil companies.

A._Badger

If this thread has achieved one thing it's reminded me why I've never wanted to own a diesel.

Ultrasonic

A._Badger wrote: »

If this thread has achieved one thing it's reminded me why I've never wanted to own a diesel.

Why is that? I can see why the end of this thread could put you off wanting a diesel with a DPF, but more widely?

goonarmy

A._Badger wrote: »

If this thread has achieved one thing it's reminded me why I've never wanted to own a diesel.

Diesels wih veggie oil equals cheap motoring. Whats not to like?

Richard53

jase1 wrote: »

Either way, unless someone can come up with some evidence that the supermarket fuel does not meet specification, this thread is going nowhere.

As I posted earlier, I don't think it's a question of meeting specification. My experience is that my diesel car runs fine on either branded or supermarket diesel, but that whenever I have had a problem (rough running, reduced mpg) it has been after filling at Tesco, and that a tank of branded fuel has restored the performance. In other words, not the specification of the fuel as such, but problems with individual tankfuls.

I suspect it is a matter of occasional contamination rather than either sub-spec fuel or an engine that can't cope. But it has never happened with branded fuel, only with Tesco, and I draw my own conclusion from that.

Joe_Horner

Richard53 wrote: »

I suspect it is a matter of occasional contamination rather than either sub-spec fuel or an engine that can't cope. But it has never happened with branded fuel, only with Tesco, and I draw my own conclusion from that.

Fair comment, although my experience is exactly opposite - my only issue ever with fuel contamination was from a "big oil" brand filling station. I choose not to take that as even suggesting that there's an endemic problem with their fuel.

I don't know what overall market share is like for the various companies but I'd suspect that, on an individual filling station basis, the supermarket brands deliver far more fuel to far more customers every day than most branded stations.

If that's true then it'd be reasonable to expect a larger number of apparent problems to arise with them even if they were serving exactly the same fuel, with exactly the same additives, from tanks maintained by exactly the same maintenance companies.