With their patented welding process at the core of stainless steel railcar construction, the cars produced by Budd were a truly unique product. The articulated design of some Budd-Michelin cars, with trucks shared between adjacent cars, presented another opportunity for weight saving with the new train. On conventional passenger cars, each carbody rode upon a pair of trucks (pivot-mounted wheel-axle assembly), with one truck at each end. The articulation not only reduced the number of trucks under the train, but it also dispensed with the need for couplers between each of the carbodies, further reducing the train's weight. The concept was used by Budd engineer Walter B. Dean to build a train consisting of three semi-permanently attached cars. It did, however, mean that train lengths could not be easily changed by switching out cars. The other major problem Ralph Budd faced was to find a powerplant adequate to drive a trainset at a speed competitive with the faster steam trains. The existing gasoline powerplants for motorized railcars were inadequate and gasoline engines showed limited potential for higher capacity hauling applications. Contemporary four-stroke marine and stationary diesel engines had low power-to-weight ratios and were only efficient under a narrow range of operating conditions, rendering them unsuitable for rail transport. Spark-ignited petroleum distillate engines also suffered from low power-to-weight ratios along with being maintenance-intensive and smokey. The solution to Budd's problem presented itself in the new two-stroke diesel engines developed by General Motors' Winton Engine Corporation, which represented a factor-of-four improvement in power-to-weight ratio over the previous generation of diesel engines. Their efficient operating range was also improved, owing largely to improvements in fuel injection developed by GM and Winton. A diesel-electric system driven by a prototype of the new design was used to power General Motors' automotive assembly exhibit at the 1933 Century of Progress Chicago World's Fair. Budd saw the compact, efficient system in action, saw a major piece of his lightweight train puzzle fall into place, then approached GM about adapting their engine for rail propulsion. GM accepted the challenge of developing their engine into a production series, introduced as the Winton 201A in early 1934. The result was a diesel-electric drive system developed by GM's subsidiary Electro-Motive Corporation, powered by an eight-cylinder, 600 hp Winton 201A diesel engine, installed in a new three car stainless steel streamliner within a year.