Sisal composites exhibit a high strength-to-weight ratio, although its automotive application is restricted due to weak fiber-matrix interface bonding. A new method was created to produce multiphase composites by using silicon carbide nanoplatelets (SiC), sisal fibers and an epoxy matrix. Vacuum infusion molding (VIM) was employed to manufacture the composites and a bath sonicator was used to exfoliate the SiC for equal dispersion. The composites enhanced with 0.255 wt% SiC exhibited the most notable enhancement in mechanical characteristics. Many mechanical characteristics of the composites were pointedly improved: tensile strength increased by 34.2%, tensile modulus increased by 65.7%, flexural strength increased by 21.8%, flexural modulus increased by 26.9%, interlaminar shear strength increased by 39.3% and fracture toughness mode-II increased by 21.3%. Multiphase composites improved their water absorption resistance by as much as 8%. The enhancements were credited to the more even distribution of SiC and better adhesion to the fiber's surface. Vehicle dashboards, interior walls and trunks could all benefit from the composite material's use.