The Powertrain Analysis and Computational Environment (PACE) is a forward-looking powertrain simulation tool that is ready for a High-Performance Computing (HPC) environment. The code, written in C++, is one actor in a comprehensive ground vehicle co-simulation architecture being developed by the CREATE-GV program. PACE provides an advanced behavioral modeling capability for the powertrain subsystem of a conventional or hybrid-electric vehicle that exploits the idea of reusable vehicle modeling that underpins the Autonomie modeling environment developed by the Argonne National Laboratory. PACE permits the user to define a powertrain in Autonomie, which requires a single desktop license for MATLAB/Simulink, and port it to a cluster computer where PACE runs with an open-source BSD-3 license so that it can be distributed to as many nodes as needed. Due to its origins in Autonomie, PACE benefits from the reputation of Autonomie as a validated powertrain modeling tool capable of simulating the advanced hardware and control features of modern vehicle powertrains. But PACE brings a completely new capability to ground vehicle concept evaluation and design because it permits unrestricted operation within a high-performance cluster computing environment. The software architecture of PACE and its modular development methodology will be described in the paper, along with the unique workflow that begins with powertrain definition in Autonomie and ends as a federate in the multi-physics ground-vehicle co-simulation running on a Linux operating system on a cluster computer. An example of the extensive verification testing of PACE is presented.