A chassis dynamometer, also known as a rolling road dynamometer, measures the power output of a car at its driving wheels.

The at-the-wheels figure is less than the engine's power output at the flywheel because of losses through the transmission and tyres. Some chassis dynamometers are able to conduct a coast-down test which measures transmission and tyre losses. Using this data, an estimate of the engine's flywheel power can be made.

See also engine dynamometer.