What is the power of engine that pulls a 1000 kg automobile at a steady speed of 10 m/sec along a level road?

Answer 1

in the absence of any friction, no power needed.

P is N-m/s
N = Force = ma
no acceleration, no force, no work, no power.

Answer 2

you have to have some measure of friction? (both air, wind, and road, and tire)