You sure they weren't using that special BP 100+ Octane race fuel that they sell at like, 8 select petrol stations near race courses?
Not trying to start an argument, but I seriously doubt that Super gives you that much more over normal. Maybe 10-15 but not 40. I thought the main benefits of super were slightly cleaner and better additives for the engine, and a little more power.
No way that super gives 40-50 bhp improvement, I would be shocked if it even gave 10.
its not a gain of 40-50 bhp on super, it means you get the full performance of the car, becuase thats what its tuned to. by running on unleaded, your loosing 40-50bhp.