Power inverter assemblies are provided herein for use with motor vehicles. An inverter assembly may have a symmetrical structure configured to convert DC input power to AC output power. The inverter assembly may include a housing enclosing a symmetrical DC input portion, a symmetrical AC output portion, a DC link capacitor, and a gate drive portion having a pair of power modules. The symmetrical DC input portion can include a DC input bus bar sub-assembly to which the DC link capacitor is coupled, and a second DC bus bar sub-assembly that may electrically couple the DC link capacitor with the power modules. The symmetrical AC output portion may include a three phase output AC bus bar sub-assembly to which the power modules can be electrically coupled. A cooling sub-assembly may be provided for cooling the power modules with fluid transfer using a coolant.