Combined with an engine prototype, the dynamometer allows researchers to control the tiniest variables to assess performance.

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The engine is mounted on a test-bed and attached to a computer-controlled dynamometer, which is used to apply an adjustable load.

ECONOMIST: Car design

He then drives the car onto a dynamometer, a big contraption that measures the engine's torque and horsepower while the car runs standing still.

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It might be doable on a dynamometer in a testing lab.

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But when Dr Narici strapped his heel-wearers' ankles into a dynamometer, which can measure a foot's turning force, the readings were indistinguishable from the control group's.

ECONOMIST: Anatomy and behaviour

In terms of reliability impact, more and more work is done in the lab, typically on a dynamometer (a device which measures force), to prove the major mechanical systems on the car.

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