Premium unleaded - worth it?

fivetide

Joe_Horner wrote: »

Sounds more like a case for blaming Jag for using dodgy materials in their fuel systems that can't cope with BS standard fuel than blaming Tesco for supplying fuel to that standard

Also sounds very similar to the common "bought a diesel to save fuel but only ever go to the shops and back in it thus causing lots of issues" syndrome.

5t.

EdGasket

No that jag was used on long journeys to/from work every day. It is true that the design of the early 2L Jag diesel can't cope with impurities due to the fine injector nozzles but the experience does suggest more impurities in supermarket diesel.
Another instance - colleague at work with petrol Honda Civic. He was using supermarket unleaded. Engine check light kept coming on. Honda told him to run on premium fuel instead. Problem went away. However as the premium fuel was expensive, he tried branded normal unleaded which has been fine also.
Conclusion: supermarket fuel is of poorer quality. I have given two instances that show this to be true in practice and in the first case it is backed up with fuel analysis and advice from Jaguar. Remember all those lamda sensors mucked up a few years back by Tesco unleaded?

Lum

Interesting post here.

First some background. It used to be the case that all the motor fuel used to conform to the British Standard and the requirement to meet that standard was enshrined in law. This situation no longer applies and it is now unnecessary for a marketed petrol or diesel to meet the full requirements of the European (and British) Standard specification. The fuel must only meet the environmental controls laid down in European and, subsequently, UK legislation. So, technically, a fuel could meet the legal requirements but not be suitable for use in an engine and there is only the legal protection given by the need for the fuel to be fit for purpose under consumer protection legislation, which is far more difficult to prove after the event than the hard analysis of a fuel against detailed specification requirements before it is marketed.

This less secure situation for the consumer is made more uncertain by British and European changes to liquid motor fuel specifications enforcing the incorporation of biofuel components. This has caused a major and ongoing reappraisal of, first, the fuel specifications; secondly, the tests used in those specifications and, thirdly, the limits which will apply in those tests - all necessary to meet fit-for-purpose criteria. Biofuel components are natural materials and their compositions can vary. They too have specifications which are subject to evolution as both the motor and fuels sectors come to terms with biofuel blends. The intention in Europe is that the proportions of biofuels components will increase from the present 5 % to 10 %. With some vehicle handbooks limiting biodiesel blends to 5 %, for example, for sound technical reasons, the quality of motor fuels has never been so uncertain at a time when engines are becoming more sophisticated to meet increasingly stringent exhaust emission legislation.

Three road tankers drive into a refinery distribution terminal and load up with fuel. One has a small amount of quality-boosting additive added. The next has a larger amount of additive added, while the third has a higher performance base fuel again with additive incorporated. Additives and high performance base fuels cost more and give greater protection or performance. That is why some oil companies have produced higher quality fuels which they sell at a premium. Basically the old rules apply. Generally, you get what you pay for, and if fuel is being sold very much cheaper in a particular area then the motorist has to ask himself or the petrol retailer why. Caveat vendor!

Source(s):
RMI Petrol Retailers Association Technical Consultants

Joe_Horner

Yes, it's an interesting post Lum, but seems to be at odds with this "guidance to industry" from the NWML regarding the legal requirements of pump labelling:

http://www.bis.gov.uk/assets/nmo/docs/legislation/legislation/liquid-fuel-and-lubricants/lfl-guidance.pdf

It certainly gives the impression that all pumps must be labelled to confirm that the fuel complies with the full (updated) British Standard and that failure top do so is an offence.

Certainly, labelling pumps as dispensing a fuel that meet a given BS spec when the fuel doesn't meet that spec in full would be a guaranteed way to get shut down very quickly indeed - especially if it was routine across your several hundred forecourts.

I think those who doubt will find that all pumps at their local supermarket carry the relevent British Standard, so the fuel WILL meet those standards in full.

Again, those are the standards that the car makers say you can use, so if your car gives a problem using them it's the car maker at fault, not the fuel supplier (assuming it's not a random "bad batch" of fuel of course). For example, if they design injectors that clog with the size of particulates that the BS says the fuel can contain then they've got their design wrong!

A._Badger

EdGasket wrote: »

No that jag was used on long journeys to/from work every day. It is true that the design of the early 2L Jag diesel can't cope with impurities due to the fine injector nozzles but the experience does suggest more impurities in supermarket diesel.
Another instance - colleague at work with petrol Honda Civic. He was using supermarket unleaded. Engine check light kept coming on. Honda told him to run on premium fuel instead. Problem went away. However as the premium fuel was expensive, he tried branded normal unleaded which has been fine also.

Which makes it even more curious that Honda told me it doesn't matter where I fill-up. Experience has suggested Honda was right.

EdGasket wrote: »

Conclusion: supermarket fuel is of poorer quality. I have given two instances that show this to be true in practice and in the first case it is backed up with fuel analysis and advice from Jaguar. Remember all those lamda sensors mucked up a few years back by Tesco unleaded?

A false conclusion, then. The sensor issue was due to the contamination of a batch of fuel This was widely documented and acknowledged at the time. It had nothing whatsoever to do with the general quality of supermarket fuel.

gkerr4

EdGasket wrote: »

No that jag was used on long journeys to/from work every day. It is true that the design of the early 2L Jag diesel can't cope with impurities due to the fine injector nozzles but the experience does suggest more impurities in supermarket diesel.
Another instance - colleague at work with petrol Honda Civic. He was using supermarket unleaded. Engine check light kept coming on. Honda told him to run on premium fuel instead. Problem went away. However as the premium fuel was expensive, he tried branded normal unleaded which has been fine also.
Conclusion: supermarket fuel is of poorer quality. I have given two instances that show this to be true in practice and in the first case it is backed up with fuel analysis and advice from Jaguar. Remember all those lamda sensors mucked up a few years back by Tesco unleaded?

i think this is a load of rubbish - it's the same fuel from the same (i think there are only 4 or 5) refineries in the country. The notable exception being the GTL type fuels such as shell V-Power.

There is a difference in the additive package on the posh diesel vs regular diesel, but in general, regular diesel is regular diesel - be it from a BP, texaco, tesco, asda whatever coloured pump.