Well, different companies owning the different refineries for a start. Different source of crude oil as a base product makes a big difference (North Sea crude is not as good as Gulf crude). Ultimately I suppose it comes down to money. Total are a global company who are serious about their fuel (from Immingham) whereas Petroplus (from Seal Sands) are a minor player in the game and don't have the resources to do a proper job.
Petroplus use exclusively North Sea crude, whereas Total get better quality crude barged in from the Gulf. It takes less work to refine Gulf crude to the required standard than North Sea stuff, and the cost cutters start screaming if too much is spent on production.
Just my personal opinion of course.
Petroplus use exclusively North Sea crude, whereas Total get better quality crude barged in from the Gulf. It takes less work to refine Gulf crude to the required standard than North Sea stuff, and the cost cutters start screaming if too much is spent on production.
Just my personal opinion of course.