The Indian locomotive class WDG-4 is a type of six-axle (Co-Co) freight-hauling diesel-electric locomotive with AC electric transmission designed by General Motors Electro-Motive Diesel in 1997–1998 for Indian Railways, where they are classed as WDG-4. Derived from the EMD SD70MAC, it is powered by a 4,000 hp (3,000 kW) 16-cylinder EMD 710G3B prime mover. Thirteen were built by EMD as order #958647, and a further eight were exported in kit form and assembled in India. The class entered service in 1999. This locomotive is also famous for, and can be identified by the distinct Jet Aeroplane-like sounding capability of its EMD 710 prime mover.

The EMD 710 is a line of diesel engines built by Electro-Motive Diesel. The 710 series replaced the earlier EMD 645 series when the 645F series proved to be unreliable in the early 1980s 50-series locomotives which featured a maximum engine speed of 950 rpm. The EMD 710 is a relatively large medium-speed two-stroke diesel engine that has 710 cubic inches displacement per cylinder, and a maximum engine speed of 900 rpm.