New York City Transit (NYCT) has established a new design train fire heat release rate to be used in all the capital projects. Having relied in the past on simplified computer modeling and different set of material properties, NYCT has used in-house expertise with an advanced computer modeling technique and fire model to derive a more credible and realistic design value. Since the early 1990's, NYCT has used 14MW for the trains, but through the use of CFD and new train material information, NYCT has established that a 5MW fire is more credible and appropriate design fire scenario. This paper presents excerpts from the report that describes the analysis carried out by NYCT, and focuses on the scenario considered as the design basis.