A reliable model for road/vehicle/driver interaction is very often needed for car design and development, and also for accidents causation and reconstruction analysis. For both uses, validity is a critical point. SERA-CD has developed a package called CALLAS for 3D road vehicles dynamics simulation. A working group was built to establish the validity of this package. This group selected 4 very different cars fitted with full data collection systems. More than 200 tests of pure longitudinal, lateral, vertical dynamics and various combination of them with progressive difficulties, up to and beyond the limit of adhesion were defined and carried out on two test tracks. Comparison between measured and computed responses were done by the group. The general conclusion is that CALLAS provides an open loop 3D dynamics response valid within the confidence interval of measured values. The results precision depends on solicitation level and car parameters relevance. For the covering abstract see ITRD E116488.