I don't know from where you are getting these facts. WDP4 was the engine used to test the Talgo series train at 180 kmph not any electric loco. WDP4 have been doing great jobs in running important trains from Kolkata to North east like Saraighat Express and Darjeeling Mail. They constantly run easily at 110 MPS wherever permissible and also have some good acceleration even after the trains being 24 coach ICF trains. HWH-NJP shatabdi runs at 130 kmph from HWH to khana using an EMD. Even BDTS-DSR Garib Rath Express runs at 120 kmph using old age ALCOs. EMDs are technically superior to any other Indian Railways Locomotives except the new WAG-12.