Supermarket fuel - does it really give lower mpg ?

maninthestreet

These claims were tested by TV programme 'Fifth Gear' a few years ago - the result was that unless you have a high-performance car, e.g Subaru Impreza WRX, supermarket fuel gives the same MPG as 'premium' grades.

intranix

petrol starts to lose its octane rating as soon as it comes out of the ground,

the additives that some use (i.e. shell) help keep this octane rating above 95 ron, supermarkets do not use any in their 95 ron, and if this fuel is stored for too long it will degrade and result in lower MPG.

Also if you fill up on a cold winters night you will get more fuel into your tank as the density is higher.

intranix

maninthestreet wrote: »

These claims were tested by TV programme 'Fifth Gear' a few years ago - the result was that unless you have a high-performance car, e.g Subaru Impreza WRX, supermarket fuel gives the same MPG as 'premium' grades.

that's not true, they tested fuel additives that you can buy in halfords, this is not the same thing. They found reduced mpg and power from these products.

this is not the same as comparing 95 and 98 ron fuel!

david39

From Intranix:

petrol starts to lose its octane rating as soon as it comes out of the ground,

the additives that some use (i.e. shell) help keep this octane rating above 95 ron, supermarkets do not use any in their 95 ron, and if this fuel is stored for too long it will degrade and result in lower MPG.

Also if you fill up on a cold winters night you will get more fuel into your tank as the density is higher.

Petrol doesn't come out of the ground - it comes out of a refinery.

In the main, it is distributed to regional centres from the refineries by underground pipeline. Because of logistics that are too complex to explain here, the time it takes for product to leave say, the Thames Refineries to reaching Manchester can be several weeks, after which, it can stay in the depot storage tanks for even longer.

Deterioration of the product over those sort of periods is microscopic and, at the time it is delivered into the supermarket tankers it has to be fully up to spec as laid down by European standards. It does not lie around under supermarket forecourts for more than a day or so because of their prolific turnover.

The sopermarkets sell fuels that meet European Union specs. The question is do they sell above those specs? The major brands do, some of the minor brands do not.

As for temperature difference in between a cold night and warm day - the difference in the fuel temperature would be practically negligible because the fuel on a forecourt is pumped from large underground storage tanks and is insulated by several metres of earth and concrete. It is, therefore, not subject to short term temperature fluctuations.

king100

david39 wrote: »

From Intranix:




Petrol doesn't come out of the ground - it comes out of a refinery.

In the main, it is distributed to regional centres from the refineries by underground pipeline. Because of logistics that are too complex to explain here, the time it takes for product to leave say, the Thames Refineries to reaching Manchester can be several weeks, after which, it can stay in the depot storage tanks for even longer.

Deterioration of the product over those sort of periods is microscopic and, at the time it is delivered into the supermarket tankers it has to be fully up to spec as laid down by European standards. It does not lie around under supermarket forecourts for more than a day or so because of their prolific turnover.

The sopermarkets sell fuels that meet European Union specs. The question is do they sell above those specs? The major brands do, some of the minor brands do not.

As for temperature difference in between a cold night and warm day - the difference in the fuel temperature would be practically negligible because the fuel on a forecourt is pumped from large underground storage tanks and is insulated by several metres of earth and concrete. It is, therefore, not subject to short term temperature fluctuations.

Your telling me that now!!! I been diggin for petrol for years and just keep finding this black stuff.

What a waste of time.

Supermarkets bog standard fuel, shell total and BP all sell standard and also sell premium, sometimes the premium same price so get that.

Temp only effects from hot to cold, hot fuel will shrink when it gets cold. They allow for this and it is cheaper than cold fuel.

When underground it will not effect the density to a degree that you will notice.

When i mean hot i mean like warm tea hot.

kwaks

Some real misinformation flying about here.

Supermarket & Branded fuel come from the same sources, mine for instance come from the Grangemouth refinary. All the tankers are filled from the same source tanks, regardless of the fuels destination. Individual retailers then add their own specification of additives.

Now if you were to run your car constantly on the best mix of this fuel and additives, then you would certainly expect to see a reward through your MPG. However a one off filling at your local supermarket will not suddenly see a dive in your economy figures.

No one can say for sure what the best additive mix is, as not all the additives will affect the MPG, some will extend the life of certain engine components. This is why all the major retailers have different characteristics and additives.

So what do I do? Simple, I fill up at the most convenient station when I require fuel. This way I get all the additives that each think is important and try to cover all bases. I don't spend a couple of quid to drive to a station to save 1p a gallon (drive an impreza, so couple quid doesnt get you far).

So my advice is just to never use the same type of fuel ALL the time, mix it up a bit and keep as many stations open as possible, at the rate of station number decline they will be pretty scarce soon anyway.

Source? Well I pump 20000 barrels of crude oil out the sea bed a day.

AdrianHi

Hintza wrote: »

I would still like to see some choice in where I buy my fuel in 20 years time so if possible support your local petrol station.

In 20 years time the choice might well be down to the left hand or right hand socket on the duel electric socket in your garage, or may be hydrogen from somewhere :rotfl:

Diesel fuel does vary quite a bit from one refinary to the next and then there are additives which in addition to cleaning and lubrication do improve how well the fuel burns. These premium fuels are, usually but not in every case just different additives or add your own additives after the pump. Such fuels then exceed the minimum requirements of BS EN590

skiddlydiddly

intranix wrote: »

that's not true, they tested fuel additives that you can buy in halfords, this is not the same thing. They found reduced mpg and power from these products.

this is not the same as comparing 95 and 98 ron fuel!

I think I saw that one and it was meaasuring different brand fuels and showing the power generated from it.I think Otimax type fuel came top and the car made substantially more power on it eg 20+bhp.

Soubrette

intranix wrote: »

I consistently get better mpg from shell fuel than asda, i've tested this out many times (yes i know how to measure it;)), i have experienced as much as 5mpg difference, i only do town driving, shell always gives better mpg, and its often the same price or 1p more a litre. Plus my local shell station has free air

You need to do a double blind test

Get someone else to fill your car up with petrol and not tell you from which source - do this as many times as possible. You then keep a record of miles per gallon but hopefully not knowing which is which would smooth out any unconscious bias you might have

Sou

property.advert

Everyone saying that it comes from the same refinery is totally missing the point. Kelloggs advertises that they do not make cornflakes for anyone else but I'll bet my left kidney that they have a hand in the pie which makes cornflakes for everyone else. The legal set up of the companies and subsidiaries only requires that some company within the group does not make cornflakes for Asda etc. Spin on the truth.

Now unless we get a petrol buyer on here who knows that the exact same stuff goes in the Shell tanker and the Sainsburys tanker, like pouring the same sugar into different cups, then we have no idea whether the refinery makes 1000 different grades of petrol and prices them accordingly. just because two tankers pick up fuel from the same refinery does not guarantee that they are picking up the exact same commodity. Fuel refineries certainly can deliver exactly what the customer wants.

My gut feeling is that there is a difference. Overseas, where I have been living, we know that some garage chains and local garages have substandard fuel. As fuel is not as highly taxed as the UK, fuel economy is not such a great issue but we do know to avoid certain brands because they just make the car run less smoothly. I would bet that they give up worse fuel consumption as well.