A study of ADC 12 (Al-Si aluminum alloy) composite is conducted as the more sustainable option of material in the automotive industry due to its durability, good elastic modulus, thermal stability, wear resistance, and high strength properties. This research is performed to identify and recognize the effect from the addition of SiC reinforce on the metal composite with aluminum act as the matrix. In this sstudy, the composite will be fabricated through a stir casting process where stirring is performed mechanically with a stirrer 4 times, 10 seconds each time with 2 seconds interval between them. Then, 1, 3, 5, 7 to 10 vf.% (volume fraction) SiC was added to each of the composite, the addition of 5%, 0,04%wt strontium, and 0,15%wt TiB were believed to enhance wettability, modify the silicon eutectic phase, and acts as the grain refiner respectively. The result obtained in this research showed an increase in hardness ADC12 composite with higher SiC content, but the result showed an optimum tensile strength is at 3 vf.% SiC. Thus, It is believed that strengthening and weakening factors from the reinforcing particle and metal matrix could neutralize the effect of each other until the optimum point of 3 vf.% SiC exhibits the maximum toughness, with tensile strength and hardness values of 236 MPa and 46 HRB respectively.