During testing, the power packs of both designs proved to have issues. The Chrysler gas turbine engine had extensive heat recovery systems in an attempt to improve its fuel efficiency to something similar to a traditional internal combustion engine. This goal was not achieved: the engine consumed much more fuel than expected, burning . The GM design used a new variable-compression diesel design.
during testing the power packs of both designs proved to have issues the chrysler gas turbine engine had extensive heat recovery systems in an attempt to improve its fuel efficiency to something similar to a traditional internal combustion engine this goal was not achieved the engine consumed much more fuel than expected burning  the gm design used a new variable-compression diesel design