A dual-purpose dynamometer assembly is disclosed including a dynamometer motor, a chassis dynamometer roll that can be driven by a vehicle wheel, and a powertrain dynamometer shaft that can be driven by a vehicle powertrain. A gearbox is disposed between and rotatably couples the dynamometer motor with the chassis dynamometer roll and the powertrain dynamometer shaft. At least one chamber wall defining a test chamber is disposed between the dynamometer motor on one side and the chassis dynamometer roll and the powertrain dynamometer shaft on the other side such that the dynamometer motor is disposed outside of the test chamber. There is at least one aperture penetrating the chamber wall through which the dynamometer motor is connected to the chassis dynamometer roll and the powertrain dynamometer shaft. Accordingly, the dynamometer motor is isolated from extreme temperatures within the test chamber.