Difference Between BHP and PS. There are a number of ways to measure the power that can be generated by a mechanical device like a car. The most popular is brake horsepower or BHP, which is a method of measurement for vehicles without the encumbrance added by connecting devices like the gearbox and transmission system. In comparison, PS is a unit of power in German. Although PS is very popular in Germany and in Europe, it is rarely seen anywhere else. There are a number of ways to get the brake horsepower of an engine using a number of devices like the De Prony brake.