torque Pronunciation Key (tôrk) n.
The moment of a force; the measure of a force'* tendency to produce torsion and rotation about an axis, equal to the vector product of the radius vector from the axis of rotation to the point of application of the force and the force vector.
In layman'* terms basically its the amount of force the engie and tranny produce at the axle to turn the wheels. More force usually indicates quicker acceleration.
horse·pow·er Pronunciation Key (hôrspour) n. pl. horse·power
A unit of power in the U.*. Customary System, equal to 745.7 watts or 33,000 foot-pounds per minute. The power exerted by a horse in pulling.
I believe this came about as cars replaced horses...Not sure what a Model A or T put out but im guessing it was so low that it was measured in the difference between horses pulling the car and the engine driving it.