The GT series also utilized six axle HTC Trucks, which allowed the locomotive to haul heavier loads at slower speeds with minimal wheelslip.

To meet customer demands of a six axle version of the popular G12, EMD created the GR12 which was slightly longer and taller to accommodate the Type-C trucks.

Finally, this model now carried the popular EMD Dash 2 electronics which improved its reliability.

The GT22CW-2 found most of its popularity in Argentina and even after the breakup of Ferrocarriles Argentinos, did the successors of that company continued to purchase more GT22CW-2s.

The GT22HW-2 was a departure from the standard production of the GT22 Series as it was a custom model designed to meet the conditions of Yugoslavia.

This multipurpose locomotive was introduced with a turbocharger (T), Head End Power (H) for passenger use and EMD Dash 2 Electronics (-2), with an A1A-A1A axle arrangement.

Due to the locomotive's compact appearance, the length was shortened by 1.25 feet (380 mm) from a normal GT22CW-2.

Designed exclusively for the RFFSA by Equipmentos Villares S.A., the GT22CUM now carried a CU suffix which indicated that this model had six axles (C) and traction motors that could fit from one meter to 5 ft 6 in (1,676 mm) gauge tracks (U).