[paulca]

Also... it depends on how you look at the physics as to whether torque or power is the figure you want.

Air resistance is a force. Torque is a force. In a static moment in time it is the torque figure you are interested in. Particularly the torque at the wheels.

If you are looking at the given situation over a period of time....

Distance = Speed * Time
Force * Distance = Work done
Power = Work done / time taken.

So in that example, power is the figure you would want. They are ultimately (power and torque) the same thing expressed differently. You can always rearrange the equations to get one from the other.