Big Brand vs Supermarket Fuels

[CJXY]

Ok ok ok, I know this has been done to death... but im resurrecting it

So, I've pretty much always used ASDA/Morrisons fuel as it's cheaper and in my old MK2B and '06 GP, I never noticed any difference between them, economy wise.

I've been doing the same in my 2012 Punto (1.4 8v 77) since I got it in September. Recently, the Shell next to Morrisons on my daily drive has been price matching them, or within 1p/l, so I've been using Shell Fuelsave (bog standard unleaded), and bizarrely after only a couple of tankfulls I have noticed a marked increase in MPG, I'm up about 5-6MPG on my average - which is approx a 15% fuel saving !!! (!!!!!!) :slayer:

As far as I can tell I've not really been doing anything different, same daily drive, same driving style, etc... so unless it's down to the recent warmer weather, I can only conclude that this is indeed better fuel

I've always been in the 'the bog standard fuels are all the same' camp, but, perhaps not. As long as they are price matching the big supermarkets, I think I'll stick with it.

Anyone else noticed any differences in MPG between supermarket fuels and big brand standard fuels ?

As a sidenote, I'm not sure what fuel Arnold Clark stick in brand new cars, but on my first drive I got 51.61mpg, then it dropped off to ~38, but averaging 42-43mpg - now hitting 48-49mpg !

 

[Ulpian]

A friend of mine with a Nissan Note automatic, used for the same daily commute of 50 miles on an A road dual carriageway, and practically nothing else, found exactly the same saving by switching from Tesco to BP. In his case it was accidental, but he's sticking with BP.

I use BP anyway, and before that Shell (the franchise changed), so I can't make a comparison.

 

[catnash]

Same here, noticed when I had my Civic, the Shell on my way to work is the same price as Tescos. I wont touch supermarket fuel.

 

[Urbex]

I have a 1.4 t-jet engine.

90% motorway miles.

Did Shell Regular Unleaded (fuelsave) for 6 weeks @35mpg

Have run Shell Vpower (now nitro+) unleaded since @40-41mpg

Average run of 60 miles a day

Have 5p off vpower voucher anyway so would not go back. Give me the vpowah all the time.

In addition, engine tone is noticeably different and smoother when running vpower.

Had to full up at Tesco before a 300 miles drive home once, I cried all the way home.

Do the maths and at 3p per litre more (in my case) it works out at significantly less PENCE PER MILE which is more important than MPG imo.

Bare in mind this is a '1.4 turbo / performance engine', I don't believe the effect will be quite as significant on a bog standard 1.2 / 1.0 etc etc.

 

[Ziggy122]

I have a 1.4 t-jet engine.

90% motorway miles.

Did Shell Regular Unleaded (fuelsave) for 6 weeks @35mpg

Have run Shell Vpower (now nitro+) unleaded since @40-41mpg

Average run of 60 miles a day

Have 5p off vpower voucher anyway so would not go back. Give me the vpowah all the time.

In addition, engine tone is noticeably different and smoother when running vpower.

Had to full up at Tesco before a 300 miles drive home once, I cried all the way home.

Do the maths and at 3p per litre more (in my case) it works out at significantly less PENCE PER MILE which is more important than MPG imo.

Bare in mind this is a '1.4 turbo / performance engine', I don't believe the effect will be quite as significant on a bog standard 1.2 / 1.0 etc etc.

As long as there is a Knock sensor - it'll make a difference

i havent got enough figures and consistancy to say here

But i've used super market Super and there is a difference there too!

So its a case of trying and finding out over lots of tanks

Ziggy

 

[RuSZ]

I traditionally use Sainsbury's Super Unleaded or BP Standard.

I always get the same MPG and the Sainsburys Super is 2p a litre less

 

[Caravadossi]

...bizarrely after only a couple of tankfulls I have noticed a marked increase in MPG, I'm up about 5-6MPG on my average - which is approx a 15% fuel saving !!! (!!!!!!) :slayer: ...

I suspect there’s quite a bit of room for error in your figures.
A “couple” of fills won’t be of much use statistically.
There’ll likely be re-fill error depending how accurate a brim-up.
I suspect your av.mpg had already improved before you switched to Shell.
I suspect your last figure 48.3 (02Jun) is based on fuel you haven’t burnt yet - that makes your penultimate figure 45.4 (25May) based on Tesco fuel & not Shell.
I don’t see where the +15% fits – your last figure shows a +6% (48.3/45.4) improvement over the previous, assuming that the two data sets are reliable.
How likely is it that a 15% improvement can be expected from switching from Morrisons 95RON to Shell 95RON?

042115Z

 

[CJXY]

I suspect there’s quite a bit of room for error in your figures.

There's not, I track it manually on a spreadsheet, and both Fuelly and an App I use roughly agree, using the same data. I assume they do a bit of rounding - but I don't.

A “couple” of fills won’t be of much use statistically.

I suspect it might be 3 Shell fills in a row, rather than 2... but still. 17 fills in total.

There’ll likely be re-fill error depending how accurate a brim-up.

I run it as empty as a I dare, normally to within 0.5L-1.5L from bone dry, and it gets brimmed to the click, 45.007L is the most I've managed to get into it.

I suspect your av.mpg had already improved before you switched to Shell.
I suspect your last figure 48.3 (02Jun) is based on fuel you haven’t burnt yet - that makes your penultimate figure 45.4 (25May) based on Tesco fuel & not Shell.

It was up and down before, which I suspect the cold weather had something to do with... but I'd be surprised if it was responsible for this sort of improvement. Re the figures... no, it's based on the following calculation:

Mileage since last fill up / (Amount of fuel used / 4.54609)

468 miles / (43.623L / 4.54609) = 48.77175159892717 MPG, we'll call it 48.8 !

If you'd like to see the raw data since I got the car, to double check my calculations I'll happily post it.

I don’t see where the +15% fits – your last figure shows a +6% (48.3/45.4) improvement over the previous, assuming that the two data sets are reliable.

The +15% is the increase from my average of all fill-ups (43 MPG) since I got the car in Sept, if I exclude the last 3 fills that average is 42.8, if I include them it's 43.4MPG.

How likely is it that a 15% improvement can be expected from switching from Morrisons 95RON to Shell 95RON?

^^ THAT is exactly the point of this thread. When I sat and looked at the figures, it surprised me, a lot !

Cheers,
Chris.

 

[jatkinson]

When tesco have there 5p or 10p off i use there fuel there standard stuff.. but normaly i use bp normal derv . and get the same mpg , i do over 120 mile anight so get though it , and get the same mpg (according to fuely)

 

[Caravadossi]

... The +15% is the increase from my average of all fill-ups (43 MPG) since I got the car in Sept, if I exclude the last 3 fills that average is 42.8, if I include them it's 43.4MPG.

^^ THAT is exactly the point of this thread. When I sat and looked at the figures, it surprised me, a lot !

Thanks for data, Chris
I can see your leaving re-fuels a bit late with a 10 gal tank!

If you now say you’ve filled up 3 times (not 2) on Shell, then you’ve only burnt two fills - you’re still running on the third, & will be until 12/06(?).
Fill #18 will give a result for your third tank of Shell.
Effectively you’ve only been running on Shell from 09/05 - up to the 08/05 you were on Morrison’s.
Prior to Shell you were achieving around 43.5 on Morrison’s.
A +15% improvement on your 43mpg (or 43.5) will need to meet & sustain 49/50mpg from fill #18 .

The positive note from this data is – it’s all transparent on fuelly.

I think there's also an argument that mpg improves over time with a new engine.

051045Z

 

[CJXY]

Thanks for data, Chris
I can see your leaving re-fuels a bit late with a 10 gal tank!

Indeed I do Once I hit the red line, I figure I have about 10 miles, thanfully I haven't run out yet... but i do need to stop playing chicken with my fuel light !

If you now say you’ve filled up 3 times (not 2) on Shell, then you’ve only burnt two fills - you’re still running on the third, & will be until 12/06(?).

I see your point, so we'll see what this one works out at... but so far it's looking good... 225 miles so far on this tank, and I'm only just over a third of the way through it !

Fill #18 will give a result for your third tank of Shell.

Make that Fill #19 , I've adjusted my Fuelly stats as my first ever fill up was skewing things a bit higher... I'd included the 15L (third of a tank) the dealer gave me with the car, and the resulting 131 miles with the stats for the first fill... so I have now separated that out, and it's brought my average down to 42 !

Effectively you’ve only been running on Shell from 09/05 - up to the 08/05 you were on Morrison’s.
Prior to Shell you were achieving around 43.5 on Morrison’s.
A +15% improvement on your 43mpg (or 43.5) will need to meet & sustain 49/50mpg from fill #18 .

The positive note from this data is – it’s all transparent on fuelly.

I think there's also an argument that mpg improves over time with a new engine.

Point taken, but as I say it's looking good so far.

I really am struggling to understand HOW this sort of improvement is possible. I do drive efficiently, but I haven't changed my driving style, that I know of.

Maybe it's a combination of the new engine running in, now at ~6800 miles, the warmer weather, and the change in fuel... could all those things together be responsible for that sort of increase ?

 

[Caravadossi]

... Maybe it's a combination of the new engine running in, now at ~6800 miles, the warmer weather, and the change in fuel... could all those things together be responsible for that sort of increase ?

I don’t think Shell ever claimed a saving of over 3%(?) & in advertising went for a figure of 2% (or at least 2%?).
I’m a big believer in the weather being a major variable in mpg claims – wind resistance, temp, dewpoint etc.
For example Glasgow Airport Met gives the wind for 11:50 as 220 degrees @ 4 knots – at 11:20 it was 300 degrees @ 4 knots. (checkwx.com>EGPF>METAR)

I was looking for data on Total fuel yesterday & came across a report on Shell Fuelsave.
Shell claimed switching to FuelSave can save 1L of a 50L fill. But the ASA held …

We noted that Shell had provided substantiation which showed that over 10% of the car models they had tested for both the unleaded and diesel versions of FuelSave would, on average, achieve fuel savings of at least 2%. However, we considered that data relating to just four models of car for each fuel did not constitute adequate substantiation that 10% of all motorists could achieve one litre of fuel savings in every 50 litre fill-up. We concluded that the ads were misleading.
Full text: http://www.asa.org.uk/Rulings/Adjudications/2011/10/Shell-UK-Ltd/SHP_ADJ_154707.aspx

But would be interested in what cars they used in tests.

061115Z

 

[TallTom]

Managed 45,17l in my car once that was interesting getting to the petrol station!

 

[CJXY]

Well, we have an update:

Brim to brim, 42.77L used... gave me 478.1 miles, so:

478.1 / (42.77 / 4.54609) = 50.82 MPG

I can only say that I hope to god :worship: that this trend continues !