The PHEM simulation tool was developt by Graz University of Technology (TU Graz) in cooperation with Forschungsgesellschaft für Verbrennungskraftmaschinen und Thermodynamik (FVT). PHEM is a detailed model for 1Hz simulation of single motor vehicles and vehicle fleets.

Model Features

  • User-friendly software for calculating exhaust, brake and tyre emissions for all vehicle categories for all driving conditions in 1Hz resolution and as a cycle average
  • Generic average vehicles for all relevant vehicle categories, propulsion systems and EURO classes are pre-installed and correspond to the HBEFA data set
  • Calculation of drive and braking power as well as relevant speeds from the vehicle longitudinal dynamics simulation
  • Exhaust emissions from emission maps via engine speed and power and simulation of exhaust gas aftertreatment (e.g. SCR) and electrified powertrains
  • Calculation of cold start extra emissions from the energy turnover after starting
  • Calculation of tyre and brake wear from friction power and engine speeds (PM, PN)
  • Evaluation of measured driving cycles with regard to the savings potential through a more ecological driving style (consumption and emissions)
  • Interface to micro-scale traffic models (e.g. VISSIM, Aimsun)


Typical Model Applications

  • Used for elaboration of HBEFA emission factors for passenger cars, light commercial vehicles and heavy duty vehicles. Implementation of two-wheelers in progress for HBEFA.
  • Using HBEFA "average vehicles" for generation of emission factors for special local conditions (user defined data on driving cycles, road gradient, ambient conditions, ambient conditions, loadings etc.)  
    Example: Comparison of vehicle emissions for speed limit 30 km/h vs. 50 km/h from measured velocity trajectories
  • Research and engineering tool
    Example: simulation of thermal conditions in the exhaust system for layout of waste heat recovery systems
  • Link with micro-scale traffic models (e.g. VISSIM, Aimsun)
    Examples: Traffic light optimisation, high quality air quality modelling
  • Academic use (teaching)

Overview of input data and methods

  • Driving cycles as speed and gradient or altitude over time in 1 Hz
  • Generic average vehicles contain all the necessary input data. Changes to loads, masses, gear ratios etc. can be easily made in the GUI
  • Batch mode allows efficient batch processing of combinations of many different cycles and vehicles


The sofware is distributed as executable code and a license file to run PHEM on two computers. PHEM has a huge data base for different cars, HDV and LDV from which also input fiels for the "average" vehicle categories were elaborated. Data files can be provided for the following vehicle categories:

    • Passenger Cars (diesel, gasoline, EURO 0 to EURO 6d)
    • Light Duty Vehicles (diesel, gasoline, EURO 0 to EURO 6)
    • Heavy Duty Vehicles (diesel, EURO 0 to EURO VI, split into weight categories)
    • Buses
    • Coaches
    • Motorcycles (gasoline, EURO 0 to EURO 6, split into capacity categories)

    Further details and pricing can be found in our product flyer.

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