I was told by a tanker driver all the fuel from the refinery is the same except obviously some put there additives in like shell/texaco. My only concern is how can we 100% trust they put enough of the additives in or what they claim? Theres scams in every business these days and i dont think anyone goes around measuring and testing fuel for additives or am i wrong? Putting millers in myself means i know its def in every time i fill up and only costs £2 a tank instead of an extra £8 for the shell/texas stuff.

If you must have more "additives" then dosing it yourself and using the cheapest fuel out there is probably the best way to do it.

Never used anything but standard supermarket diesel myself for the past 200k miles, it has never caused a problem.

And since I spreadsheet every single fill, I also know that using the "super" fuels gave me no added mpg whatsoever.

Put me firmly in the "snake oil" camp. MY2016 HSE D SDV6 - gone due to fuel dilution problems.

By the age of 50 you have the face you deserve - George Orwell.

As an ex-employee of a major petroleum company, and having done a short stint of management training in Stanlow refinery some years ago, I can assure you it's all pretty much the same stuff guys. For it to be "on spec" it must meet BS/EN590 which makes provision for standards of Cetane Index, Cetane Number, Density, sulphur content, flash point, water content, carbon residue - to name but a few, regardless of brand. It all comes from the same refineries. The refinery will blend a Shell batch today and an Esso batch tomorrow, etc. each will have their own formulation of additives in, but in diesel fuel these make very little difference, as opposed to gasoline where there can be some significant differences. However, it does provide a USP for each company's PR team and advertisements.

Not that any major oil company would want you believing that.

You might think you notice a difference, but that is typical human bias and any difference your personal numbers show are far more likely to have been affected by ambient temperature or driving style than additives.

The only way you'll ever notice a difference is if one filling station has a low turnover which may allow condensation in their tanks to accumulate and increase water content. However, with the demise of rural "Ma & Pa" filling stations giving rise to much greater turn over at the remaining facilities, this is not so likely to occur these days.

Hope this helps.

Regards,

Old Jock 2018 (MY19) Jaguar F-Pace R-Sport 300PS Petrol in Caesium Blue with many bells and whistles.
2015 RRS HSE SDV6 Firenze Red with Santorini Panoramic Glass Roof, gone but not forgotten.