 Several years earlier, EMD had made similar versions of the SDP45 and SD45 in a full-width cowl unit, which it named FP45 and F45.Although the SDP40F was externally nearly identical to the FP45, EMD chose not to give the new locomotive a similar name such as FP40.EMD wanted to avoid adding a new locomotive type to their catalog due to price controls in effect in the early 1970s.