A 1-D heat transfer model was also developed and validated against the experimental measurements. The algorithms calculate the heat transferred through the turbocharger by means of lump capacitances. Compressor maps were then generated for a range of speeds and temperatures of the exhaust gases at the inlet to turbine and the efficiency drop associated with heat transfer was quantified. Based on the data generated by the model, a new correlation for the compressor non-adiabatic efficiency was found by means of a multiple regression analysis; the work is based on a statistical description of the different parameters that affect the heat transfer model.