what does horse power do for a car?

Answer 1

Horsepower is the ABILITY to pull the vehicle. If you have a mac truck and a 100HP engine then you have no get up and go but put that 100 HP in a rice burner and WOW they feel they have the world by the tail. Oh ya put the oversized exhaust on it to SOUND like power. No one ever got substantial HP from Exhaust that's like Custom wheels make it go faster too.....

Answer 2

Hello,

usually you measure mechanical power in horsepower. In metrics, you measure it in kW (kilowatts). The power of the engines in vehicles is expressed in this unit. In general
power = k * torque * rotary speed (in k you can incorporate a multiplier factor conform to units you use for expressing torque and speed).

(Note: what you feel when you accelerate is actually the torque, not the power !!!)

When you calculate in metric system, you don't need this k factor: P(W) = M(Nm) * Omega, where the rotary speed (-> frequency) is: Oemga = 2 * Pi * f(Hz). f = n(RPM) / 60.

1 horsepower equals 0,736 kW. Or 1 kW equals 1,36 HP.

When they give the power of the car., they refer the peak power rating of the engine. The torque makes the engine to rev, the product of torque (give in ft lbs or N m) and the engine speed (usually given in RPM) produces a power which can be used to propel the car through the driven wheels (through the powertrain). The engine hasn't got a constant torque across the engine speeds and have a maximum torque. At a given engine RPM, the torque gives a power. Measuring and connecting these points you get power/torque curves. The max. power and torque is two characteristic information (but it doesn't say much !!!). these curves can be made on engine dynamometers (-> dynos), the reading are valid in full throttle.
So power is depending from RPM and torque, it expresses the strength of the engine. Simply stated, the more the engine turns with a given torque, or the more torque is at a given RPM, the more power you have.

Diesel engines have their peak point in low RPM's (1500-2000), they are flexible in the everyday traffic. However from mid-range RPM's the torque dramatically decrases, thus the power curve starts to fall off rapidly. At the RPM where the power curve no longer elevates, the engine's power band ends.

Petrol engines have a lower torques in low RPM (approx 50-60% of peak), usually have their peak torque int the middle, thus accelerating more rapidly from low speeds. Since the peak torque is at a higher RPM, the peak power is also higher (remember, power is a product of RPM and torque). So the petrol engine can be revved to have peak powers, at the sake of fuel economy. In return we get a wide power band.

I hope this helps to figure out power (HP).

Answer 3

gives it the go.....Esp pulling out onto the freeway.....

Answer 4

thats their get up and go... how fast it can accelerate