Supermarket Fuel - Bad Buy?

worried_jim

Calm down dear. Opinions can be dangerous, stick to the facts, to help you do this I and other users have posted a link for you-
www.fuelly.com

No need to thank me.

Ultrasonic

jackthenipper wrote: »

This thread isn't/wasn't a scientific experiment, just opinion of supermarket fuel.

Though life might be easier if this weren't true, opinion that is not supported by facts is pretty useless I'm afraid.

alastairq

One of my wives tried diesel once.....didn't work at all well.

FreddieFrugal

alastairq wrote: »

One of my wives

You have more?

alastairq

IanRi wrote: »

You have more?

Oh yes....!

casual13

My original thread was not based on 'scientific fact' - merely what the Golf computer tells me as my mpg over a tankful of Shell vs. a tankful of Tesco.
Incidentally, my brother-in-law used to sell fuel additive (i.e. lead) to the refiners - which was a dying industry (!) - but he believes there is a significant difference with major brands.

cardinalbiggles

casual13 wrote: »

but he believes there is a significant difference with major brands.

He can believe what he wants, its not correct.

Ultrasonic

casual13 wrote: »

My original thread was not based on 'scientific fact' - merely what the Golf computer tells me as my mpg over a tankful of Shell vs. a tankful of Tesco.

Is it a petrol or a diesel out of interest? It is certainly possible there is a difference, particularly with the diesel which does have a higher Cetane Number than typical supermarket fuel i.e. it is measurably different, although whether in a way that significantly affect fuel economy is debatable and could certainly vary with engine. The ASA ruling I referred to in my first post also didn't conclude there were no differences, just that there wasn't the evidence to support of the claimed improvements across a range of vehicles:
http://www.asa.org.uk/Rulings/Adjudications/2011/10/Shell-UK-Ltd/SHP_ADJ_154707.aspx

If Tesco and Shell fuel cost the same then you may as well buy Shell. But if Shell is more expensive and you really want to make an informed decision I have two thoughts:

1) The mpg displayed by car trip computers can be wildly innaccurate. You'll get more accurate results using old fashioned brim-to-brim measurements (most accurately done by always refueling with the same pump).

2) There are lots of factors that affect the mpg of a tank besides fuel. These include: how you drive, what sort of driving you do (city or long motorway cruise), the weather, how much you use air conditioning and in car fans etc. To really compare the performance of two fuels you want to have all of these conditions as similar as you can between tanks. Always using the same fuel gives significant variations between tanks for all of these reasons, as my Fuelly history above shows.

arcon5

The MPG calculator on my car reads about 13-15mpg out. From what I read most Mondeos will be out to an degree.

But having driven 36k miles over the last 11 months I certainly can't see any difference between the return on supermarket and branded fuel. Well at least nothing I can't put down to driving style and servicing of the car.

alastairq

I know it's been asked before...but....who 'owns' Harvest fuel?

I ask [again, probably]....because a nearby fuel spot went from Shell to Harvest, and I have used it [petrol, not diseasel]....and noted a certain 'crispness' to performance for the duration....and wondered?