Does anyone know why WAP 4s are not upgrading for HOG, is there any technical limitation or IR just don't want to?? Cz IR has huge fleet of P4 and they have very much time left on tracks and they are very efficient and one of the most successful loco, and since IR is now focussing more on HOG enabled train and currently only P7 (except 1 P5) are capable for that so is not required for P4 also have HOG facility to serve wider range of trains.