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In recent years we have seen drastic improvements of the accuracy of wheel force transducer (WFT) systems /1, 2 and 3/. These systems in most cases are calibrated just statically. What is the dynamic behaviour of the sensor? What can we expect towards the accuracy of the measured loads on real road surfaces as they are influenced by a number of parameters? In the present paper quantitative results are reported out of a broad investigation of the effects of the following parameters road surface, rim stiffness, tire air pressure, velocity and wet road conditions. The unique Wheel and Tire Testing Vehicle (“Universal Skid Resistance Measurement Device”) of Stuttgart University was used for the measurements on two highways. The WFT-signals are referenced to the multiaxial force sensing of this vehicle. These findings are compared to results derived from a rolling road flatbelt test stand reported in /6/.

An important part of vehicle development are design evaluation and validation processes based on testing in the laboratory. At present there are many complete vehicle, body and suspension road simulator configurations. They all are compromised with respect to complexity and cost. They all have certain advantages and disadvantages. Examples for the evolution of such systems will be discussed. It becomes apparent that new solutions are required if not just the optimization of components and subassemblies is aimed at but the exact evaluation of service life in terms of proving ground kilometers. The new concept is a complete car test rig with an active restraint system which restrains the car during maneouvre load simulation and leaves it otherwise relatively uninfluenced. The test rig has in total 20 actuators, four at each wheel and another four at the restrained system. This test rig will be described in some detail.