What is the relation between Torque and engine power?

Just wanted to know how power is distributed to wheels in a car.

  • 5
    This question appears to be off-topic because it is not about maintenance or repair
    – Nick C
    Jul 23 '13 at 10:44
  • 1
    It's useful to know. Jul 23 '13 at 15:49
  • 1
    I feel this type of question (seeking understanding of automotive systems) is rather inconsistently flagged. Perhaps my comment belongs in meta, but my personal vote on this question is "let it ride"
    – mac
    Jul 24 '13 at 17:10
  • I think this is really a duplicate - going to point it that direction.
    – Bob Cross
    Jul 11 '14 at 20:48

The torque is how strong your engine is. Power (Horsepower or kiloWatts) is how fast it can use that strength. To figure out how much work the car is doing, one uses the following formulas:

for Horsepower: Power (HP) = Torque (lb.in) x Speed (RPM) / 63,025 for kiloWatts : Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488


You've actually asked two different questions.

There is a very simple, mathematical relationship between torque and power. The power P generated at any given point in time is equal to the torque T produced at that time multiplied by the angular velocity w (i.e. engine RPM) at that time.

P = T * w

As to how the power is distributed to the wheels, that's the job of the transmission, differential, and half-shafts.

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