The purpose of this study was to compare motions and loads between the Test device for Human Occupant Restraint (THOR) and post mortem human surrogates (PMHS) in frontal impact sled tests with a focus on the head‐neck complex. The overall focus of the project was to evaluate the biofidelity characteristics and derivation of THOR‐specific injury criteria. Experiments were conducted at low, medium, and high velocities using a custom‐designed seat. Upper and lower neck forces were determined from load cell signals and locations. Based on motion and load variables (x‐ and z‐displacement profiles; maximum x‐ and z‐displacements; timing of motion vectors; upper and lower neck axial and shear forces and bending moments), it was concluded that the repeatability performance of the THOR dummy is acceptable at all tested velocities. This type of evaluation using many variables adds confidence to the evaluation/use of any device for a range of external frontal impact insults. Judging by similarities in the upper and lower neck loading profiles and maxima, it was further concluded that the THOR mimics the human head‐neck responses well at all velocities. The THOR can be used effectively in frontal impact crashworthiness tests regardless of the change in velocity.