Sabhi diesel loco aise hi chalte hai, sirf EMD nahi. Internals mein bahut difference hai. ALCO aur EMD ke diesel engines ka design different hai. Aur, pehle ALCO mein DC ( Direct current) generator or DC motors use hote te, aur EMD mein AC ( Alternating current) generator aur AC motors use hote hain.
WDP4/WDG4 jaise locos bahut modern hai, ALCO 50 years ki pehle ka technology hai, toh isiliye EMD bahut acha performance deta hai. ALCO mein bhi IR ne kaafi improvements ki hai ( WDM3D etc) aur yeh bahut kaabil locos hai, lekin EMD ke paas aur jyaada advantages hai.