BHP (Brake Horse Power) or HP (Horse Power) is an imperial measure of power defined as 33,000 foot*pound/min, or 550 foot*pound/sec. The equivalent in metric units is 76.0402 kg*metres/sec.
The "metric" or continental measure of horse power known as PS (PferdeStarke) in german or CV (Cheval Vapeur) in french is a slightly different measure defined as 75 kg*metres/sec. One PS is therefore slightly smaller than one BHP, 1 PS = 0.98632 BHP
therefore a 172 makes 169.65bhp