The M-series Studebaker trucks came in several versions both pre and post WW II. The M-5 was a 1/2 ton PU. The M15 was the 3/4 ton version. The M15A was the one & 1+1⁄2-ton version. The M5, M15, and M15A all came with the Champion 169 ci. engine, only. The M16 1-1/2 & 2 ton versions came with the more powerful Commander 226 ci. engine. The Studebaker US6 version was produced during the war to government specifications; using a different nose and engine configuration, in both a 4x6 & 6x6 versions of a 2+1⁄2-ton truck. In early 1945, Studebaker was given permission to produce some M Series trucks for civilian use. These early post war civilian trucks used the Studebaker US6 cab with the government style swing out windshield.