What Materials Are Used in Cars Today

Modern cars are made from a mix of metals (primarily steel and aluminum), plastics and composites, glass, rubber, copper wiring, and—especially in electric vehicles—battery materials such as lithium, nickel, cobalt, manganese, and graphite; advanced electronics also add silicon, silicon carbide, and rare-earth magnets. These choices balance safety, weight, cost, performance, manufacturability, and sustainability, and they vary by vehicle type and market.

The core structure: metals that form the backbone

Steel and advanced high‑strength steel (AHSS)

Steel remains the single largest material in most vehicles, thanks to its strength, crash energy absorption, and cost-effectiveness. Automakers increasingly use advanced high-strength steels—press-hardened steel, multi-phase and third-generation AHSS—to cut weight while meeting tougher safety and emissions standards. These grades enable thinner panels without sacrificing rigidity, and they’re widely used in body-in-white, safety cages, door beams, and crash structures.

Aluminum for lightweighting

Aluminum cuts mass and improves efficiency, so it’s common in hoods, doors, suspension components, wheels, and increasingly entire body structures in premium or performance models. High-pressure die-cast aluminum “megacastings” are expanding in 2024–2025 to integrate large chassis and body sections in one piece, reducing parts count and simplifying assembly. Aluminum also dominates thermal systems and battery enclosures due to its conductivity and corrosion resistance.

Magnesium and other light metals

Magnesium alloys appear in steering wheels, seat frames, and instrument panel supports, where every gram matters. Their use is still limited by cost and corrosion considerations. Titanium, while rare due to price, can feature in high-performance exhausts and fasteners. Zinc and tin are used in coatings and small die-cast parts.

Plastics and composites: shaping interiors and aerodynamics

Automotive polymers and where they’re used

Plastics reduce weight, enable complex shapes, and improve durability and aesthetics. The following list highlights common polymers and typical applications.

• Polypropylene (PP): bumpers, interior trim, underbody shields
• Polyurethane (PU): seat foam, NVH insulation, sealants
• Acrylonitrile butadiene styrene (ABS): dashboards, pillar trims, bezels
• Polycarbonate (PC) and PC blends: light lenses, glazing elements
• Polyamides (PA, e.g., nylon 6/6): intake manifolds, under-hood components
• Polyethylene (PE): fuel tanks (ICE), canisters, liners
• Polyoxymethylene (POM): gears, clips, precision mechanisms
• PVC and TPO: interior skins, weather seals

Together, these polymers deliver weight savings, cost control, and design flexibility, while meeting strict flame, odor, and durability standards for interiors and exteriors.

Fiber-reinforced composites

Glass-fiber composites (GFRP), including sheet molding compound (SMC), are used for body panels, liftgates, springs, and structural inserts. Carbon-fiber-reinforced polymers (CFRP) appear in roofs, hoods, and tubs on high-end vehicles, where maximum stiffness-to-weight is critical. Natural fiber composites (hemp, flax, kenaf) reinforce panels and trims to reduce weight and improve sustainability.

Glass, rubber, and other everyday essentials

Beyond metals and plastics, cars rely on specialized glass and rubber compounds for visibility, safety, and road grip. The list below outlines key materials and their functions.

• Glass: laminated safety glass for windshields; tempered glass for side/rear windows; increasingly, laminated panoramic roofs for noise reduction
• Tires: blends of natural and synthetic rubber (e.g., SBR), carbon black and silica fillers, steel and textile cords
• Elastomers and seals: EPDM, silicone, and nitrile rubber for weatherstrips, gaskets, hoses

These materials must withstand UV, temperature extremes, chemicals, and mechanical stress, ensuring safety, comfort, and durability across the vehicle’s life.

Electrical and electronic materials: the vehicle nervous system

Copper and wiring

Copper powers the harnesses, motors, and busbars that carry current throughout the car; aluminum is sometimes used in larger gauge cables to save weight. Connectors employ engineered plastics and corrosion-resistant platings (tin, nickel, silver).

Semiconductors and power electronics

Traditional silicon chips control everything from airbags to infotainment. For EV powertrains, silicon carbide (SiC) MOSFETs are increasingly standard in inverters—especially in 800‑volt architectures—thanks to higher efficiency and lower losses. Gallium nitride (GaN) devices are gaining ground in onboard chargers and DC‑DC converters, emphasizing compactness and efficiency.

Magnets and rare earth elements

Permanent-magnet motors use rare earth elements such as neodymium, praseodymium, and dysprosium for high power density. Some automakers deploy induction or wound-field motors to reduce rare-earth dependence, trading off efficiency or packaging. Electrical steels with precise laminations minimize losses in motors and transformers.

Batteries in EVs and hybrids

Electrified vehicles add battery materials that dominate both mass and cost. The following list summarizes common chemistries and key components found in modern packs.

• Cathodes: LFP (lithium iron phosphate) for cost and durability; NMC/NCA (nickel–manganese–cobalt / nickel–cobalt–aluminum) for higher energy density
• Anodes: graphite (often with silicon blends for higher capacity)
• Electrolyte and separator: LiPF6 salts in organic solvents; polyolefin separators
• Current collectors and enclosures: copper (anode), aluminum (cathode, casings, cooling plates), structural aluminum for pack frames
• Emerging options: sodium‑ion (hard carbon anode; Prussian-blue or layered oxide cathodes) in entry-range vehicles and stationary storage

LFP is expanding rapidly in 2024–2025 for mainstream, standard‑range EVs due to cost and thermal stability, while high‑range models tend to favor nickel‑rich chemistries; sodium‑ion is early-stage in cars but growing in select markets.

Finishes, safety, and comfort materials

Paint systems include phosphates, cathodic epoxy e‑coat for corrosion protection, basecoats, and clearcoats. Structural adhesives (epoxy, acrylic, polyurethane) bond mixed materials and improve crash performance while reducing weld count. Airbags are typically nylon 6,6; seat foams are polyurethane; interior textiles increasingly use recycled PET microfibers and bio-based coatings. Acoustic foams, mastic pads, and laminated glass manage noise, vibration, and harshness (NVH).

Typical material breakdown by weight

Shares vary by segment (compact vs. pickup), powertrain (ICE vs. EV), and design. The ranges below describe common compositions for contemporary passenger vehicles.

• Ferrous metals (steel + iron): about 50–60% (higher on many ICE vehicles; lower on some aluminum-intensive models)
• Aluminum: roughly 8–15% (higher in premium, performance, and EV platforms)
• Plastics and composites: about 8–12%
• Rubber (including tires): about 5–7%
• Glass: about 2–3%
• Copper and other nonferrous: about 1–2% in ICE, up to 3–4% in EVs
• Battery pack materials (EVs): roughly 15–30% of total vehicle mass, depending on pack size and chemistry

These figures are indicative, not absolute; specific models can deviate significantly based on performance targets, cost, regulation, and manufacturing strategy.

Sustainability and recycling trends

Automakers are boosting recycled and bio-based content to meet carbon targets. Recycled (secondary) steel and aluminum are mainstream; closed-loop aluminum recycling is expanding. Interiors increasingly use recycled PET and ocean-bound plastics, and natural fibers reduce petrochemical use. Battery recycling capacity is scaling to recover lithium, nickel, cobalt, copper, and aluminum; new regulations in major markets set minimum recycled content and traceability requirements through the 2020s. Design-for-disassembly and repairability are growing priorities alongside life-cycle assessments (LCAs).

Why these materials are chosen

Material selection is a multi-variable trade-off: strength and crash safety versus mass and cost; corrosion resistance versus manufacturability; NVH comfort versus weight; and performance versus recyclability. The rise of electrification pushes systems toward higher-voltage electronics, thermally conductive structures, and robust, recyclable battery architectures.

Summary

Cars blend steels, aluminum, plastics, glass, rubber, copper, and sophisticated electronic materials; EVs add battery chemistries and power semiconductors that now define much of the vehicle’s mass and cost. As regulations tighten and electrification grows, the mix is shifting toward lighter, more recyclable metals and polymers, efficient power electronics, and battery systems engineered for both performance and circularity.