This paper presents the Toolox 44 steel’s experimental and statistical machinability optimizations conducted for achieving minimum output parameters (energy consumption (), cutting force (), surface roughness (), and vibration (Vib)). Turning experiments have been performed under dry machining conditions on a CNC lathe at different cutting parameters according to the Taguchi L27 orthogonal array. Taguchi-based gray relational analysis (GRA) has also been used to optimize output parameters simultaneously. Moreover, analysis of variance (ANOVA) has been applied to determine the effects of cutting parameters on output parameters. As a result, the lowest Ec was measured 0.06 kW at the 1.5 mm depth of cut, 220 m/min cutting speed and 0.4 mm/rev feed rate. At 0.5 mm depth of cut, 220 m/min cutting speed and 0.1 mm/rev feed rate, the lowest , and Vib are measured at 132.28 N, 0.69 m and 2.25 m/s², respectively. According to GRA, the best machining combination in terms of energy consumption (), cutting force (), surface roughness (), and vibration (Vib) was A1B3C1, and the percentage of improvement in the gray relational degree has been calculated to be 25.25%. Validation test results showed that the optimization of cutting parameters was successful in the machining process of Toolox 44 steel according to the multiple output parameter values.