This paper describes the effects of variations in vehicle response characteristics on driver-vehicle disturbance responses using a moving base driving simulator. Two exploratory studies are discussed, one dealing with vehicle transient response characteristics and the other with steady state characteristics. Close correspondence with full-scale data reported by others indicates that dynamically realistic simulators can be effective research tools. The flexibility of the simulator has facilitated the collection of other preliminary data which extend the full-scale findings. Considerably more effort will be needed, however, before strong arguments either for or against specific parameter boundaries can be made.