The growing awareness regarding environmental issues is prompting a transition from synthetic fibers to plant fiber-reinforced composites for eco-friendly applications across the automotive, aerospace, and marine sectors. In this study, we evaluated the impact of the silicon carbide (SiC) additive on the mechanical and water absorption (WA) characteristics of hybrid composites (HC) made of snake grass (SG) and luffa cylindrica (LC) fibers. Tensile analysis showed that the presence of 7.5 wt% SiC raised the tensile strength (TS) to 59.22 MPa with an increase of 38.91%. However, the increase of SiC to 10.0 wt% resulted in a reduction of strength to 53.21 MPa, with a 24.82% improvement, due to weakened adhesion between the fiber and matrix. The neat composites (SG/LC) exhibited a flexural strength (FS) of 61.27 MPa. The maximum FS was 78.63 MPa at 7.5 wt% SiC; however, increasing SiC content to 10.0 wt% led to a reduction in strength to 72.36 MPa because of particle aggregation. Impact testing results confirmed that adding SiC enhanced the fiber-matrix interface, thereby improving load transfer and enhancing the HC's ability to absorb and dissipate impact energy. The WA behavior of the SG/LC-SiC composites showed improvement with increasing SiC content, achieving a minimum of 14.89% at 7.5 wt% SiC, which is due to improved interfacial bonding and reduced voids. This research underscores the benefits of HC materials prepared from SG and LC fibers for applications in vehicle interiors and construction, such as wall panels and separators. Highlights: Incorporating 7.5 wt% SiC increases tensile strength by 38.91%. Flexural strength reaches a peak of 78.63 MPa with the inclusion of 7.5 wt% SiC. Water absorption decreases to 14.89% at 7.5 wt% SiC inclusion. © 2025 Elsevier B.V., All rights reserved.