Inspired by the Hispano-Suiza 8, some of which were captured and tested, the Benz Bz.IIIb was a fairly large engine, but its performance was disappointing. Despite not being accepted for service use a number of late World [War I] prototype German aircraft used the Bz.IIIb, the Benz IIIbo and the geared Benz IIIbm. The latter suffered vibrationproblems.