More scientific graph for engine

I am trying to find a more scientific graph to describe engine performance than the conventional
rpm-hp-torque.

I believe the new graph should X axis of speed, Y axis
as drive force on wheel (power/speed). And it should have multiple lines in this graph, each line represents
result for a gear chosen (first gear, second gear...)

Then, we can easily decide which gear to use at any speed, just pickup the gear that provides best drive force.