Sasol - I used to own a Fiesta 1.0T eb and it had intermittent cel when I exclusively filled at Shell until I started filling at Sasol. Coincidentally I had taken my car for its annual service and Ford updated the ECU for emissions tsb and filled it up with Sasol and it's never had any cel until I sold it before it ecoboomed on me.
Base fuel made to the same specifications with some additives, only exception is the lowest sulphur content diesel which is Sasol only from what I recall.