The aspect of compatibility between large and small cars has become a main topic in recent accident research. The likelihood of collisions between vehicles of considerable different size is triggering latest discussion on new legal requirements and test procedures.

Computer modelling applicable in crashworthiness has advanced substantially due to the availability of mature software and powerful hardware. Design guide lines derived from theses calculations are no longer restricted to A-B-comparisons and rough trend analyses. This paper describes a compatibility study based on full scale finite element and lumped mass model calculations involving models exceeding 140000 elements.

A head-on car-to-car offset crash is compared to a car-to-deformable-barrier simulation. The cars have a weight ratio of approximately 1.5:​1. We describe the efforts of obtaining a single deformable barrier which gives similar deformation and deceleration profiles for both vehicle as in case of the car-to-car collision.