VocabDictionary
nounneutral connotation

Roller dyno

A diagnostic device that measures a vehicle's power output by having the drive wheels rotate a set of heavy steel rollers.

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Nuance Analysis & Word Contrasts

The term 'roller dyno' is the standard industry parlance for a chassis dynamometer. It is distinguished from an 'engine dyno' by the fact that the engine remains inside the vehicle and transmits power through the drivetrain to the rollers. Use 'roller dyno' in casual or semi-technical automotive contexts; use 'chassis dynamometer' in formal engineering reports or professional documentation.

roller dyno vs engine dyno

A roller dyno measures power at the wheels (accounting for drivetrain loss), whereas an engine dyno measures power directly at the crankshaft, isolated from the vehicle's transmission.

roller dyno vs rolling road

These are synonymous, though 'rolling road' is more common in British English, while 'roller dyno' is the dominant term in North American automotive culture.