Does Supermarket Fuel Produce Lower MPG?
Discussion
valverguy said:
Without reading everything above, my old man works for a large refinery in our local area. I know that all fuel in the local area regardless of brand comes from the same place, yes additives are added to speification, however he says that getting your fuel from whereever is the busiest garage is the best bet... why? simples because the longer fuel is stored waiting to be used the less combustable it becomes, suddenly your 99ron becomes 95 after a week of not being used. Ive alwas gone to our local asda because its the busiest garage around and never had any problems 
It's true that fuel 'goes off' but it's nowhere near as fast as you make out.Think months or years and you're in the right field - a week is nothing whatsoever.
I believe some high performance petrol engines respond better to higher octane rating fuels; perhaps their 'knock sensor systems' are able to compensate and allow the engine to produce more power? Otherwise we would all be driving around using 88/89 RON fuels?
Refresh my memory but didn't one of the major supermarket chains (Tesco's, Sainsbury's?) have serious problems with their petrol a few years ago caused by the incorrect mixing of additives that took place at one of their service stations? If this is the case then obviously their fuels supplied to joe public were different to those supplied at other petrol stations.
Refresh my memory but didn't one of the major supermarket chains (Tesco's, Sainsbury's?) have serious problems with their petrol a few years ago caused by the incorrect mixing of additives that took place at one of their service stations? If this is the case then obviously their fuels supplied to joe public were different to those supplied at other petrol stations.
In my experience, diesel is far more varied between outlets as opposed to unleaded. My old 330d would run poorly on Sainsburys diesel but was fine on Shell/BP/Total. I've run 2 M3's and an M5 on my local Sainsburys super unleaded for about 4 years in total and have had no issues. Makes sod all difference running them on Shell/BP as I tried that for a couple of months (approx 6 tanks worth) and there was no difference to performance or mpg.
GrumpyV8 said:
Refresh my memory but didn't one of the major supermarket chains (Tesco's, Sainsbury's?) have serious problems with their petrol a few years ago caused by the incorrect mixing of additives that took place at one of their service stations? If this is the case then obviously their fuels supplied to joe public were different to those supplied at other petrol stations.
IIRC it was imported fuel which had been transported in the tanks of a ship which had not been cleaned out properly. The fuel was contaminated and started to 'foul' the oxygen sensors of the vehicles unlucky enough to have filled up with it. This covered a number of outlets and had nothing to do with the base fuel which was of correct octane rating etc. and all to do with contamination.I read the motoring correspondent of the D. Telegraph swears by Shell V-Power claiming it's blend of additives together with octane rating keeps the internals of an engine cleaner and better protected than other fuels. He also advocates the use of V-Power diesel for similar reasons but I have no experience of this.
Perhaps it is simply(?) the mix of fuel additives that make the difference which Shell would obviously not make available to other companies.
Perhaps it is simply(?) the mix of fuel additives that make the difference which Shell would obviously not make available to other companies.
Garvin said:
There is no difference in the basic fuel used, the difference, as stated previously, is in the additives most of which are to do with keeping the engine/injector internals clean etc. I have used many different brands over many different vehicles and there is no significant difference in mpg as long as the everything is kept crud free which the 'expensive' brands tend to do and the supermarket offerings do not do so well. One could use supermarket fuel and run, say, 250ml injector cleaner through every 3k miles or so but the current net savings over 3k miles are ~£18 or about £72 a year (on a total fuel bill of ~£2.4k) for something doing average annual mileage (12k miles) at 30mpg. Indeed, the saving without the injector cleaner is ~£92 per annum - one has to way this saving up against the health of one's engine!
If your vehicle does not have an adaptive ecu with knock sensors etc. then you are pretty much wasting your time buying higher octane fuel if it's tuned to run on 95RON and you're expecting increased mpg.
I would expect those vehicles that have been run on an exclusive diet of supermarket fuel for years to not have their internals in particularly rude health and not be running at optimum mpg. Swapping to some 'better' fuel which starts to clear the crud out could conceiveably result in bad running/worse mpg until it's all cleaned through, especially for the adaptive ecu equipped vehicles which may detect all this crap and start to either wind things back a bit or try and compensate.
For others who experience bad running on certain fuels I would think that this is more to do with the cleanliness of the fuel station storage tanks than anything else.
I think there is definately something in this. I usually get 42-44mpg on long motorway runs. I stopped to fill up just before a 200mile trip at a total on the A1. Normal, smooth motorway driving and I only got 35mpg out of that tank! I usually get 38 around town!If your vehicle does not have an adaptive ecu with knock sensors etc. then you are pretty much wasting your time buying higher octane fuel if it's tuned to run on 95RON and you're expecting increased mpg.
I would expect those vehicles that have been run on an exclusive diet of supermarket fuel for years to not have their internals in particularly rude health and not be running at optimum mpg. Swapping to some 'better' fuel which starts to clear the crud out could conceiveably result in bad running/worse mpg until it's all cleaned through, especially for the adaptive ecu equipped vehicles which may detect all this crap and start to either wind things back a bit or try and compensate.
For others who experience bad running on certain fuels I would think that this is more to do with the cleanliness of the fuel station storage tanks than anything else.
johnpeat said:
A difference of 2-3mpg on a car which averages (and I'm guessing) 35-40mpg is a small difference even over 20,000 miles. When you consider that a car's MPG is influenced by a huge range of factors (the driver, the weather, the road surface, traffic, tyre wear, fuel mix, supplying forecourt etc.) it's easily explained away.
Same applies to the others who've found the opposite of course.
End of the day, supermarket 95RON is the same as everyone else's 95RON bar some additives which are mainly intended to clean your engine (and will take time to achieve this).
Anyone who thinks otherwise has been gulled by advertising/brand image and snobbery.
I understand there are many variables, but I do have a very consistant week driving wise and a very consistant driving style. Winter sees me lose 2/3mpg on avergae, seeing 40mpg on a motorway run for example compared to 44 in the summer. However the I can do one week idedntical to the next with shell and morrisons and I will see 36 in the shell, and 40 in the morrisons. I've repeated this a few times and seen exactly the same thing.Same applies to the others who've found the opposite of course.
End of the day, supermarket 95RON is the same as everyone else's 95RON bar some additives which are mainly intended to clean your engine (and will take time to achieve this).
Anyone who thinks otherwise has been gulled by advertising/brand image and snobbery.
There isn't a huge amount in it, but generally with morrisons I will get to 330miles before I fill up. On shell I'll be on fumes by 300 miles.
Tbh, I have no idea why I see the difference but the fact is that I do. It's also nice that morrisons is usually 1 or 2 ppl cheaper.
Regarding the petrol grade/performance difference - as I understood from Honda (we raced their engines for a few years always trying the highest grades and sometimes enhancers) the ecu would indicate an almost immediate difference in performance when there was a change from high to low octane fuel but when high octane was re introduced the performance was re gained over a long period. There was no difference in running (ie pinking under load etc. and temperatures were always constant).
We always ran the highest RON available for racing (after an ecu reset) - but then.......... I ran the Evo x on 95 for a few miles until I could get to some proper fuel on the same journey last week, there was a marked difference between the two grades in acceleration which knocks all that b
ks I wrote above into nonsense (perhaps turbo engines are more sensitive with lower CR)
We always ran the highest RON available for racing (after an ecu reset) - but then.......... I ran the Evo x on 95 for a few miles until I could get to some proper fuel on the same journey last week, there was a marked difference between the two grades in acceleration which knocks all that b
ks I wrote above into nonsense (perhaps turbo engines are more sensitive with lower CR)Loteuk said:
...... perhaps turbo engines are more sensitive .....
I noticed a great difference in performance (but not in mpg) using 97 RON v 95 RON in the 1.8T turbo'd engine I ran in a Mk 1 TT whilst not a great deal of difference in the subsequent 3.2 V6 normally aspirated engine I ran in my next TT. So, yes, my experience is that turbo engines do respond better to the higher octane fuels.Regarding instant adaptation from high octane to low I assume this is to immediately prevent damage from 'pinking' i.e. winding back ignition timing pretty quickly whilst only advancing the ignition timing, when going from low octane to high, in a slow and controlled manner to, again, ensure no damage occurs.
I notice that I get better mpg and (I think) smoother running from the normal Esso stuff than from Tescos regular unleaded. It costs the same, and keeps me happy, so I will stick to it!
There is certainly a difference, my mate's XR2 hates Tesco stuff and runs like crap with it compared to Shell / Esso. Must be the different additives?
There is certainly a difference, my mate's XR2 hates Tesco stuff and runs like crap with it compared to Shell / Esso. Must be the different additives?
Garvin said:
Loteuk said:
...... perhaps turbo engines are more sensitive .....
I noticed a great difference in performance (but not in mpg) using 97 RON v 95 RON in the 1.8T turbo'd engine I ran in a Mk 1 TT whilst not a great deal of difference in the subsequent 3.2 V6 normally aspirated engine I ran in my next TT. So, yes, my experience is that turbo engines do respond better to the higher octane fuels.Grayedout said:
I work for a company that supplies additives to many of the UK fuel suppliers and the answer is yes fuel qualities do differ between companies.
All base fuel in a particular area will come from the same refinery but each company then has its own type and amount of additive added.
Each company will define a minimum performance level that its fuel much achieve and this is achieved by using different additives or more or less of the same additive.
In terms of mpg then yes one of the benefits of a better fuel is more efficient burning and hence less fuel required to achieve the same bang !
Out of interest - where would you prefer to fill up you car?All base fuel in a particular area will come from the same refinery but each company then has its own type and amount of additive added.
Each company will define a minimum performance level that its fuel much achieve and this is achieved by using different additives or more or less of the same additive.
In terms of mpg then yes one of the benefits of a better fuel is more efficient burning and hence less fuel required to achieve the same bang !
ryandoc said:
Sorry to pick on this post as an example as there's many, but 100% complete and utter bks I'm afraid.
Anyone who thinks a refinery process produces crap fuel 12 hours a day and sticks it in X tank as crap stuff then produces good stuff the other 12 hours and sticks it in Y tank doesn't know what they are talking about.
Road loading terminal, 4-5 filling hoses, all supplied from same tanks. Additive is added at the nozzle/point of entry into the tanker compartment. Base fuel is same generally all third parties get the exact same additives, bigger brands get their own.
Also as of June this year Shell no longer own a refinery in the UK so who's make their fuels for them.
Flow measurement engineer for Shell, extensive knowledge of tanker loading at a certain ex Shell refinery on the wirral.
That's not willy waving before anyone chips in. Just can never get over the conspiracy theories people come up with on fuel in the UK in the 21st century.
V-power uses a GTL (gas to liquid) component which is basically C1 methane converted to a synthetic petrol. All other super fuels use ethanol. Road grade ethanol is not certified water free where as v-power has no ethanol. In some countries v-power can be used in light aircraft.
That's pretty much how I understood it to work. I guess the real question should be what the differences are in the additive packages?ks I'm afraid.Anyone who thinks a refinery process produces crap fuel 12 hours a day and sticks it in X tank as crap stuff then produces good stuff the other 12 hours and sticks it in Y tank doesn't know what they are talking about.
Road loading terminal, 4-5 filling hoses, all supplied from same tanks. Additive is added at the nozzle/point of entry into the tanker compartment. Base fuel is same generally all third parties get the exact same additives, bigger brands get their own.
Also as of June this year Shell no longer own a refinery in the UK so who's make their fuels for them.
Flow measurement engineer for Shell, extensive knowledge of tanker loading at a certain ex Shell refinery on the wirral.
That's not willy waving before anyone chips in. Just can never get over the conspiracy theories people come up with on fuel in the UK in the 21st century.
V-power uses a GTL (gas to liquid) component which is basically C1 methane converted to a synthetic petrol. All other super fuels use ethanol. Road grade ethanol is not certified water free where as v-power has no ethanol. In some countries v-power can be used in light aircraft.
When I had a Boxster I was pretty anal about only using V-Power or similar 98/99 RON in it.
Since moving to the Freelander 2 I use mostly Sainsbury's Diesel in it and haven't noticed any issues.
The way I had it explained to me, doing long runs and ensuring the engine gets properly up to temperature will do a lot to keep your engine clean so when comparing normal to premium fuels the types of journey you do can make a big difference as if you do mostly very short journeys, that tank of V-Power is helping clean the engine rather than being a huge power boost, IYSWIM.
johnpeat said:
valverguy said:
Without reading everything above, my old man works for a large refinery in our local area. I know that all fuel in the local area regardless of brand comes from the same place, yes additives are added to speification, however he says that getting your fuel from whereever is the busiest garage is the best bet... why? simples because the longer fuel is stored waiting to be used the less combustable it becomes, suddenly your 99ron becomes 95 after a week of not being used. Ive alwas gone to our local asda because its the busiest garage around and never had any problems
It's true that fuel 'goes off' but it's nowhere near as fast as you make out.Think months or years and you're in the right field - a week is nothing whatsoever.
Tango13 said:
Dave Hedgehog said:
interesting as my R32 ran like crap on BP fuel
My M5 runs like a bag of bolts on BP fuel too. Usually the fuel consumption is 20-30% worse on the dogs piss from the local BP station.t on BP Ultist, but runs fine on BP peasant fuel.This is an interesting thread and timely. I go out of my way to get Shell V-Power in my TVR (straight six 350bhp from 3.6L NA engine with no sophistication). Interesting to note that TMS' research showed I'm better off with Tesco 99RON.
I was about to ask the question whether it's worth me trying BP Ultimate (albeit 97RON). It is my closest station and prices have reversed. They used to be the most expensive with Tesco being the cheapest but now Tesco are most expensive and BP are cheapest in my area.
Not that I'm counting the pennies;). It's just more convenient to fill at BP. I'm not really interested in mpg but I am interested in performance and cleanliness for the engine.
I was about to ask the question whether it's worth me trying BP Ultimate (albeit 97RON). It is my closest station and prices have reversed. They used to be the most expensive with Tesco being the cheapest but now Tesco are most expensive and BP are cheapest in my area.
Not that I'm counting the pennies;). It's just more convenient to fill at BP. I'm not really interested in mpg but I am interested in performance and cleanliness for the engine.
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