I love those fuel tests. One car and one set of atmospheric conditions. Not hugely conclusive as far as I'm concerned! I don't care either way the V-power isn't too expensive for my mileage so I just use it. I do wonder how the fuels perform under a range of conditions. From a stinking hot track day, humid as hell soaking day, cold short trips, long motorway stint in the winter, in gear pulls again in various conditions, part throttle pick up and so on.
My old 106 diesel would do around 58 flat out in 4th on supermarket diesel up a local long national speed limit hill but would top out at around 62 on V-power. I did that journey fairly regularly over a 5 year period and it would always pull better up that hill on V-power diesel. Standard injection pump timing. I still don't consider that conclusive evidence as there are so many variables but interesting none the less. Ran fine on boggo fuel.
I miss that little engine. Had worked it ass off permenantly for 135,000miles when I sold it running sweetly, never complained, never smoked and revved to 5K which is surprisingly high for a little N/A diesel.
Going off topic again.......