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Simulations used to estimate carbon dioxide (CO2) emissions and fuel consumption of medium- and heavy-duty vehicles over prescribed drive cycles often employ engine fuel maps consisting of engine measurements at numerous steady-state operating conditions. However, simulating the engine in this way has limitations as engine controls become more complex, particularly when attempting to use steady-state measurements to represent transient operation. This paper explores an alternative approach to vehicle simulation that uses a “cycle average” engine map rather than a steady state engine fuel map. The map contains engine CO2 values measured on an engine dynamometer on cycles derived from vehicle drive cycles for a range of generic vehicles. A similar cycle average mapping approach is developed for a powertrain (engine and transmission) in order to show the specific CO2 improvements due to powertrain optimization that would not be recognized in other approaches.

There is insufficient time within a single technical elective to learn principles of internal combustion engine operation as well as specialized simulation tools such as GT Suite or Kiva. A number of authors have recognized this constraint, and they have structured their internal combustion engine text around use of programming languages such as FORTRAN, C++, and MATLAB®. This paper reports on how the capabilities of MATLAB® have been synergized with learning activities and homework assignments to set the stage for a successful final engine simulation project. The MATLAB® code involved in this effort can accept basic input parameters such as bore, stroke, compression ratio, spark advance, throttle position, RPM, air/fuel equivalence ratio, and volumetric efficiency. The code returns output power and torque using the Wiebe function and bulk temperature. The model uses a two-zone heat release model to predict power, torque, brake specific fuel consumption, and volumetric emissions.