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What is horsepower and torque in a car?


It isn’t uncommon to come across the term horsepower and torque in any car review articles or car commercials. Some car dealers even put a big note on the windscreen telling their customers how many horsepower the car has. What is horsepower and torque in a car? What does it actually means for a car with 300 horsepower? What they actually mean? Everything in this world needs a unit of measurement to determine their performance and ability especially cars. Horsepower (hp) is a unit of measurement of power. The term horsepower was invented by a Scottish inventor and mechanical engineer James Watt. In Watt’s theory, 1 Horsepower is equal to 33,000 foot-pounds per minute. This means with 1 horsepower, it can lift 33,000 pounds of weight up 1 foot in a minute, or 3,300 pounds 10 feet in a minute, or 330 pounds 100 feet in a minute, or 33 pounds 100 feet in a minute.

Now try to imagine 1 Horsepower = 33,000 foot-pounds per minute with the image shown below. If a Ferrari generates 1 hp, it can lift up a 33,000 lbs weight from one foot down the cliff in a minute. In other words, a 300 hp car is capable to move it up in 0.2 seconds. [33,000 pounds is nearly equal to 15,000 kg. (33,000 lbs = 14,968.5 kg)]

what is horsepower
What is horsepower

In fact, one horsepower in electric power measurement is equal to 746 watts. If you put the power generated by a 1000 horsepower car to an electric generator, it can generate 746,000 watts. In the automobile market today, a Bugatti Veyron Super Sport has an engine that capable to produce 1,184 bhp. Without doubt, this power is capable to heat up the entire village during winter time. See also: How much horsepower does my car have?

What is Brake Horsepower (bhp)?

Brake Horsepower (bhp) is another common term that always appears in car engine specification especially new car brochure. Brake Horsepower is the pure amount of power generated by a car engine before the loss in power caused by various auxiliary components such as gearbox, drive train, water pump, alternator, power steering pump, and etc. In recent years, the true power generated by a sports car is measured with an engine dynometer (dynamometer) or more common talking “dyno testing”. A car is pull up on a ramp and a driver will go through all gears and then pin hard on the last gear until redline during a general dyno testing. In a nutshell, a car with 300 hp on wheels is powerful than a car with 305 bhp under the hood if all the auxiliary components will cause it loss more than 5 hp.

What is torque in a car?

Torque is the power to rotate an object about an axis. It can be “turning power”, “twisting force”, or the power to accelerate in a car. Most of the sedan cars running on the road are using common internal-combustion engines that only produce useful torque over a limited range of rotational speed, typically from 800 to 6,000 rpm. Remember our article regarding a Ferrari 458 Italia? In the article we mentioned that “The 458 Italia features a direct-injected 4.5 L V8 engine that delivers 562 horsepower and 398 lb-ft of torque at 9,000 rpm.” What does the 398 lb-ft of torque do in a Ferrari 458 Italia? 398 lb-ft (foot-pounds of torque) is equivalent to 540 Nm (Newton-meters). This amount of torque is what makes the car capable to accelerate from 0 to 62 mph in 3.4 seconds. In other words, more torque, less weight, larger wheels, and more power are some factors that allows a car to accelerate faster. Up to date, some of the high torque cars in the market are Bugatti Veyron Supersport (1106 lb-ft), Hennessey Venom 1000 (1100 lb-ft), SSC Ultimate Aero TT (1094 lb-ft), Koenigsegg Agera (811 lb-ft), Mercedes-Benz CL65 AMG (738 lb-ft), Saleen S7 Turbo (700 lb-ft), etc. All these cars are famous for their acceleration power.

Understanding the relationship between horsepower (hp), brake horsepower (bhp), and torque is essential in order to build a car that is able to accelerate fast and run fast. Then, the driving pleasure will certainly be there.