Original sentence: The gear ratio of the traction motors to wheel axle determines the maximum operating speed of the locomotive; a standard F59PHI has a gear ratio of 56:21 which provides a top speed of 110 mph (176 km/h)
Edited sentence: The gear ratio of the traction motors (model D87BTR) to wheel axle determines the maximum operating speed of the locomotive; a standard F59PHI has a gear ratio of 56:21 which provides a top speed of 110 mph (176 km/h)