Dyno

Car manufacturers generally market the power and torque of their engines.

However the boy racers, after working over a car, only care about the power that gets to the road.

Which they measure with a dyno, which is a sort of a treadmill for cars that measures the power and torque at the rollers that are rotated by the car wheels.

Similarly, I often meet very intelligent people with powerful brains (engines) but fuck-all ability to get that power to the ground.

They would fail the dyno test.