This thesis analyses the factor affecting the loss of performance of a Touring Race Car. The work consists of the identification and validation of a procedure for the characterization of driving styles and circuits. The procedure identified uses some statistical instrument for the identification of outliers and comparison of different samples. This procedure can select the data, aggregate them, and consequently compare the different drivers and circuits. The data used for this research come from the database of the Six Engineers Team. More specifically it is analyzed the 2019 racing season working on telemetry data of the cars assisted by the team: two Seat Leon Cup Racer.