Yes, there could be some extra recirculation of gasses or other such thing that bleeds off a bit of the power.Aren't the emissions over the pond an absolutely ridiculous strangulator of performance?
I know in the 70's and 80's the US car market was killed by the emissions war. However, you are most right, very odd how they have 3hp difference.
P.S Only my experience but I take all I read from Wiki with a pinch of salt!!:laugh: