I agree with Richard if an hp is a bhp! But are you, Richard, familiar with the arcane UK horse-power formula of old, which gave the taxable rating of engines in the old days, and held back engine development for cooking cars appreciably? (Because a long stroke had the effect of reducing the horse-power rating - with good reason!). Austin 7, Morris 8, Standard 10, Rover 14, Rolls 20, etc etc etc. Too arcane to quote the calculation here unless you want it - and I'd have to go and check in a book.
And what's a PS anyone? I see my Yamaha has lots of them apparently, but I had never given it any thought until this thread started!