A friend of mine called me and asked why his Diesel fuel had foamed when he put into the tank, He said that looked like the foam on a glass of beer. He did say that he added a small amount of Armorall SP? to his mix. I suspect that the Amourall SP ? caused the foaming problem.
Before I reply to him, I just want to ask this perhaps silly question, To me it is a no brainer but... I would try a fuel without any Amorall to check but he is much smarter than I many times over.