 Most "old-look" buses were powered with the Detroit Diesel 6-71 inline six-cylinder diesel engine, the exceptions being the shorter models that were powered by the four-cylinder version of the same diesel engine, and buses that were equipped with gasoline engines.Manual and automatic transmissions were available, with the Spicer angle-drive two-speed transmission being used on automatic-equipped buses built prior to 1948.After 1948, the 2-speed Allison V-drive transmission was used on automatic-equipped buses.