The MP36PH-3C was the second locomotive produced in the MPXpress catalog. This version has had the most customers by far. The locomotive like the MP36PH-3S has a 16-645F3B type prime mover. All MP36PH-3C's are either Tier 2 or 3 compliant. In this arrangement, when providing HEP, the full 3600 HP from the prime mover is available for traction, and the prime mover is allowed to idle at a lower RPM. Caltrain was the first to purchase the MP36PH-3C in 2003. Today, ten commuter railroads operate this model.
- BCVX (West Coast Express.Canadian Operation.) #906 Built 2011.
- JPBX (CalTrain) #'s 923-928. Built 2003.
- MARC #'s 10-35 Built 2007, 2010-2011.
- MBTA #'s 010 and 011. Aquired from UTA in 2010.
- METX (Metra) 401, 417, 419, 420, 423. Rebuilt from MP36PH-3S
- MNRX (Minnesota Northstar) #'s 501-505, 512. Built 2008. #512 was acquired from UTA in 2011.
- VREX (Virginia Railway Express) #'s V50-V69. Built 2010-2011.
- UTAX (Utah FrontRunner) #'s 1-11, 15-21. Built 2007-2009.
- NMRX (New Mexico Rail Runner Express) #'s 101-109. Built 2005-2008.
- SCAX (Metrolink) #'s 888-902. Built 2008.