When designing automatic transmissions the performance of friction elements such as wet clutches and wet brakes is vital to the performance and durability of the transmission. In order to achieve high performing friction systems, correct selection of friction lining and transmission fluid is required. This is combined with the need for correct mechanical design with respect to torque capacity and power/energy capacity. In the later stages of development, the friction system performance can be tuned by means of the clutch control system. This is due to the control strategy together with vehicle inertia and rotating inertias in the powertrain influencing the power and energy introduced in the clutches. In order to develop the correct mechanical design and set correct levels of freedom for the clutch control optimization, the designers need to know how much the friction system can be stressed before the transmission durability begins to be influenced in a harmful way.This paper presents methods used to determine the energy and power limits of the friction systems. Data are presented from two different test stands: One similar to an SAE #2 test stand. The latter is a novel test equipment designed to monitor clutch wear and friction under different conditions in order to find the limits of energy and power at which the friction lining durability is affected in a negative way. The test stand is built at Luleå University of Technology. Several genuine Volvo parts are used while other parts are acquired or manufactured. Several design aspects were taken into consideration. Among them was easy access for assembly/disassembly of the clutch. A list of specification requirements was put together and the test stand was designed to meet these. A list of performance attributes:- The total inertia of the system is 0.63 kgm2- The system can be braked in less than 0.5 s- The system is accelerated in less than 10 s- The wear of the clutch is measured- The temperature is measured inside the clutch- The torque transmitted by the clutch is measured- The rotation speed of the system is measured- The pressure activating the clutch is measured- The pressure is controlled with high accuracy by a fast servo solenoid valveThe inertia of the system, the rotation speed and the braking time can be changed such that different power/energy levels can be achieved. The new test stand is described in detail showing the design considerations taken to make the methods reliable.