Validation tests are essential for assuring the durability of automotive structures and components. The sporadic nature of mechanical failure requires that durability testing be accelerated to reduce the test time while faithfully replicating the characteristic fatigue damage and failure modes obtained during service. This paper develops accelerated durability tests for the torsion beam axle of a rear suspension under failure-correlated load, where a particular loading input is highly correlated with a characteristic fatigue failure mode and therefore dominates the fatigue damage obtained at a failure location. This study involves several steps. First, the load histories, i.e., the wheel loads and strains at critical regions, are measured on a proving ground. Second, failure locations are identified by critical plane and biaxial ratio analyses of the strain histories and local strain states on the axle. Then, the failure-correlated load is identified by determining the correlation between the absolute maximum principal strain at the failure locations and the corresponding full-wheel loads recorded in the measured load histories. Finally, two accelerated load spectra based on the identified failure-correlated load are developed in either the time domain or the amplitude domain, and the results of the accelerated durability tests are compared with those obtained for durability tests conducted under full-wheel loading. The results show that the failure locations and fatigue lifetimes obtained using the accelerated load spectra coincide with those obtained under full-wheel load conditions, and acceleration factors between 1.75 and 2.85 were observed using the two developed spectra. The proposed methodology is expected to contribute to the development of accelerated durability tests of automotive structures and components subjected to complex multiexternal loads.