A transportable test cell for the measurement of motor vehicle emissions and fuel consumption was developed for Environment Canada. The test cell incorporates a bus containing exhaust gas analyzers and the dynamometer/exhaust gas sampling control system plus a trailer mounted electric absorption chassis dynamometer, which rejects absorbed vehicle energy into the local utility grid. The test cell was developed for testing of in-use motor vehicles with curb weights up to 2726 kg (6000 lbs) in major Canadian urban centers. It is designed for all-weather road transport and easy deployment, requiring only connections to a building power supply. The design and operation of the test cell are described, along with its intended use.