Horsepower at the rear wheels is always less then at the crank because of parasitic drag throughout the drivetrain. I believe it's measured the same regardless the country of origin, at the crank, when it comes to manufacturers claimed horsepower. The higher number is more impressive even though that's not the ponies at the rear wheels where it counts. I'm with you on the Top Gear addiction, I now have 78 episodes TiVo'd!