Fuel really makes a difference

[LostKiwi]

i always thought it came out of the ground ! and then its how we process it ? and thats where the variables enter the picture?

I theory we get it out the ground (and what we get is incredibly variable in content), then we refine it to get the fractions we want. At that point in theory the fractions from one refinery should be the same as any other (though quantities of each will depend on source).
For example the crude from Venezuela tends to contain far more heavy fractions than crude oil from Malaysia. This means we would expect more ship grade fuel oil from a barrel of Venezuelan crude than a barrel of Malaysian crude oil and conversely more petrol from Malaysian oil than Venezuelan.
The refinery fractional outputs should in theory be the same quality no matter the source.
The reality is that what we call diesel is comprised of a mix of fractions and is not a pure product so can vary from refinery to refinery depending on source crude.

 

[ajlsl600]

as thought then ground...

 

[Frontstep]

So it gets blended to ensure consistency.

This is chemistry not cooking.

All governed by British Standards.

The supermarket fuel debate has manufactured some strange arguments which have a huge underlying flaw
the same crude from the same wells has been coming for decades well before Mr Sainsbury or Mr Tesco in I think the 70's started selling fuel.