Many moons ago my missus had a bmw mini that was chipped, had induction kit and full s/steel exhaust system.
She ran it on V power or equivalent premium fuel and it ran sweet.
Once she had to put "normal" fuel in it and it ran like a dog!!
Back on V power and it was fine.
At the time I had a corsa C 1.8sri with just a McDonald's spec spud cannon and a drilled airbox with panel filter (don't ask
) with standard ecu and I tried a tank of V power and it was really bad performance wise.
When I had my vvc I put a tank of it through and although it didn't gain anymore power it seemed to run better when reverted back to regular petrol so my thoughts are it's good as a one off unless chipped and tuned stick to normal fuel but stick some in now and again.
Also, many many many moons ago I had a Morris marina 1.3hl that wouldn't run on esso fuel!!
Any other fuel and it was fine but put esso in and it'd cough n fart and wouldn't go above 70mph.
Strange.