| High-Strength Steel | Body panels, doors, roofs, fenders, chassis-visible surfaces | High strength, impact resistance, formability, and mature corrosion-protection systems | Approximately 7.8 g/cm³ | Cost-effective, widely available, repairable, and suitable for large-scale production | Higher mass than most lightweight alternatives; requires effective anti-corrosion treatment | Highly recyclable through established ferrous-metal recovery systems |
| Aluminum Alloys | Exterior panels, hoods, doors, body structures, trim, and wheel surfaces | Low density, corrosion resistance, good thermal conductivity, and high specific strength | Approximately 2.7 g/cm³ | Reduces vehicle mass and supports energy-efficiency targets | Higher material and forming costs; repairs may require specialized processes | Well suited to recycling; alloy separation and contamination control affect recycled quality |
| Polypropylene (PP) | Bumpers, wheel-arch liners, underbody shields, interior panels, and storage components | Low weight, chemical resistance, moisture resistance, and good impact performance | Approximately 0.90–0.91 g/cm³ | Lightweight, economical, easy to mold, and suitable for textured surfaces | Limited stiffness and heat resistance compared with engineering plastics; surface can scratch | Recycling is technically feasible when parts are identified and separated from mixed polymers |
| Acrylonitrile Butadiene Styrene (ABS) | Instrument panels, consoles, bezels, grilles, mirror housings, and interior trim | Good impact strength, dimensional stability, surface quality, and paintability | Approximately 1.03–1.07 g/cm³ | Supports high-quality molded and textured finishes with relatively easy processing | Moderate weathering and ultraviolet resistance unless modified or coated | Can be mechanically recycled, although additives, coatings, and mixed-material assemblies complicate recovery |
| Polycarbonate (PC) | Transparent lenses, lamp covers, glazing components, and protective interior surfaces | High impact resistance, transparency, dimensional stability, and broad service-temperature capability | Approximately 1.20 g/cm³ | Safer and lighter than glass for selected transparent components | Can scratch and yellow under ultraviolet exposure without suitable hard coatings or stabilization | Recycling is possible, but coatings, optical additives, and multi-layer parts require controlled processing |
| Polyurethane (PU) | Seat cushions, armrests, soft-touch surfaces, steering-wheel coverings, and acoustic components | Elasticity, cushioning, abrasion resistance, acoustic absorption, and comfort | Typically 0.20–1.25 g/cm³, depending on foam or solid formulation | Provides comfort and premium tactile performance across flexible and rigid forms | Recycling is more complex than for single-family thermoplastics; aging depends on heat, moisture, and chemicals | Recovery routes include reuse, chemical recycling, and limited mechanical recycling depending on formulation |
| Thermoplastic Olefin (TPO) | Exterior bumpers, claddings, rocker panels, spoilers, and protective trim | Flexible, impact-resistant, moisture-resistant, and suitable for low-gloss textured finishes | Approximately 0.90–0.96 g/cm³ | Combines low weight with durable exterior performance and good processability | May have limited paint adhesion and can show thermal expansion or surface waviness | Recycling potential is favorable when the material is kept clean and separately identified |
| Polyvinyl Chloride (PVC) | Synthetic leather, door skins, wire insulation, sealing profiles, and protective coverings | Good chemical resistance, flexibility, abrasion resistance, and weatherability when stabilized | Approximately 1.20–1.45 g/cm³ | Versatile surface appearance, cost efficiency, and availability in flexible and rigid grades | Environmental management requires attention to additives and chlorine-containing processing emissions | Recycling is possible through dedicated systems, but additives and composite constructions can hinder recovery |
| Glass | Windshields, side windows, rear windows, panoramic roofs, and display covers | High optical clarity, hardness, weather resistance, and stable performance across temperature changes | Approximately 2.4–2.6 g/cm³ | Excellent transparency, scratch resistance, and long-term weathering performance | Higher mass and brittleness than polymer alternatives; laminated structures complicate processing | Glass recovery is established, but laminated interlayers and coatings must be separated for high-quality recycling |
| Natural-Fiber Composites | Door panels, parcel shelves, trunk linings, seat backs, and interior decorative panels | Low density, vibration damping, renewable fiber content, and suitable stiffness for semi-structural interiors | Typically 1.0–1.5 g/cm³, depending on fiber and polymer matrix | Can reduce fossil-based material content and support lightweight interior design | Moisture sensitivity, variable fiber quality, and limited suitability for high-temperature exterior applications | End-of-life recovery depends strongly on the polymer matrix and the ability to separate fibers from composites |