What Is Horsepower Anyway?
Horsepower (hôrs’pou’ər)-A unit that is used to measure the power of engines and motors. One unit of horsepower is equal to the power needed to lift 550 pounds one foot in one second. This unit has been widely replaced by the watt in scientific usage; one horsepower is equal to 745.7 watts.
Coined or invented by Engineer James Watt, it’s basically the work that a single horse can do in minute. The term “horsepower” itself is used to measure output of engines, machines and electric motors among other things. It sounds simple but not really. It doesn’t necessarily follow that the higher the horsepower the faster the car. An Abrams tank has a Honeywell AGT1500 C multi-fuel turbine 1500 hp engine yet has a top speed of only 45mph while a Mercedes CLK 550 has a 5.5L V8, 32 valve, 382hp and is electronically limited to 155 mph.
So what gives? This is known as power to weight ratio which is the power output of the engine divided by the car’s curb weight. So going back to the example above, though the Abrams has a 1500hp engine, it weighs 61.4 metric tons while the CLK 550 with its 382hp engine weighs a mere 3720 lbs. Mercedes has invested a lot in R&D to maximize the power to weight ratio. Due to this, Mercedes has some of the best performing vehicles on the road today. So before you go off to see your General Dynamics dealer, you may want to think about this. By the way, MSRP of an Abrams? $4.35 million.
