How much energy is used for a unit of horsepower? And why do we still use horsepower to describe car engines?

Question

It just seems very abstract to me to say the a car has the power of 235 horses.....Anyone know why it is still used?

Answer 1

No one has come up with a better way to describe power output.
Actually that is not altogether true, there are much more accurate ways but this is what we know and use mostly from tradition. It has been standardized so that automotive horsepower ratings are the same more or less.
If suddenly we started using a different system it would be difficult to reference to what we already know.
Horses and cars both sorta evisceral, macho things, it sounds better than saying "the new Zoomba GT has 33,000 footpounds per minute of output" LOL.
Horsepower is sexy power, especially to an advertiser.

Answer 2

Horsepower and other somewhat esoteric units of measurement (e.g., grains for mass of a bullet, troy ounces for mass of gold, therms for heat energy, etc.) are still being used because they are traditionally used in that specific niche. The US is the only major country that does not use the SI measurement system. SI/metric units make much more intuitive sense than imperial units.

On the other hand, how many people in the US are going to know what you are talking about if you say your car has a 175 kW (=235 HP) powerplant?

Answer 3

A bit antiquated but it makes people, especially us guys, feel "powerful" or "big" or like "somebody". The smaller the you know what the more horsepower they want.

A unit of power necessary to raise 33,000 pounds one foot (off the ground) in one minute.

Good Luck!

Answer 4

One mechanical horsepower also equals 745.699 watts or .746 kW (kilowatts) of electrical horsepower.