What is the difference between EFI fitted WDM3A and regular WDM3A 1 Answers What is the difference between EFI fitted WDM3A and regular WDM3A EFI refers to Electronic Fuel Injection, controlled by camshaft not Common Rail (CR) Type. This EFI system will reduce the tremendous black smoke that is emitted by the loco. Moreover, this system will help in fuel efficiency |