Power-to-weight ratio

Common card · No. 301366

Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement of the actual performance of any engine or power source. It is also used as a measurement of the performance of a vehicle as a whole, with the engine's power output being divided by the weight (or mass) of the vehicle, to give a metric that is independent of the vehicle's size. Manufacturers often quote power-to-weight at its peak value, but the actual value may vary in use, and these variations can affect performance. The inverse of power-to-weight, the weight-to-power ratio (power loading), is a calculation commonly applied to aircraft, cars, and other vehicles to enable comparison of one vehicle's performance to another. Power-to-weight ratio is equal to thrust per unit mass multiplied by the velocity of any vehicle.

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