What materials are used in motor vehicles

Motor vehicles are built from a multi-material mix that typically includes steels (especially advanced high-strength steels), aluminum alloys, polymers and foams, elastomers, glass, technical ceramics, copper and other electrical conductors, composites (glass- and carbon-fiber), coatings, and—in EVs—battery and power electronics materials such as lithium, nickel, iron phosphate, graphite, silicon carbide, and high-performance magnets. The exact blend varies by vehicle type (ICE vs. hybrid vs. BEV), performance goals, cost, and manufacturing strategy.

The core structural metals

Metals form the backbone of the vehicle’s body, chassis, and many powertrain components because they balance strength, stiffness, cost, and manufacturability. The trend is toward using the right metal in the right place to meet crash, durability, and lightweighting targets.

• Steels (mild, high-strength, and advanced high-strength steels, including Gen 3 AHSS): Predominant in body-in-white, safety cages, crumple zones, and many chassis parts due to high strength-to-cost ratio and excellent energy absorption.
• Aluminum alloys (cast, sheet, extrusions): Used in closures (hoods, doors), body panels, subframes, wheels, thermal systems, and increasingly large structural castings (“megacastings”) to reduce mass and improve range in EVs.
• Cast iron and compacted graphite iron: Found in traditional engine blocks, brake rotors/drums, and some heavy-duty components where heat and wear are critical.
• Magnesium alloys: Applied selectively to reduce weight in steering wheels, seat frames, and some housings; used more where corrosion and formability can be managed.
• Titanium and nickel alloys: Limited use in performance exhausts, fasteners, and turbocharger or high-temperature parts where strength-to-weight and heat resistance matter.
• Copper and copper alloys: Essential for wiring harnesses, busbars, motors, and radiators; copper content is notably higher in hybrids and EVs than in ICE vehicles.

Together, these metals deliver the structural integrity, crash performance, and thermal handling vehicles require, while allowing manufacturers to balance cost with weight and efficiency targets.

Polymers, elastomers, and foams

Plastics and rubbers enable complex shapes, lightweighting, acoustic performance, and comfortable interiors. They are widely used for trim, ducts, housings, and energy absorption, with formulations tailored for temperature, UV, and chemical resistance.

• Commodity and engineering plastics: Polypropylene (PP) for interior trim and bumpers; polyethylene (PE) for tanks and liners; ABS/PC-ABS for dashboards and bezels; polycarbonate (PC) for lenses; polyamides (PA/nylons) for underhood components; PBT and PET for connectors and housings; PMMA for lighting lenses.
• Elastomers: EPDM for weather seals; SBR and natural rubber for tires; NBR/HNBR for fuel- and oil-resistant seals; fluoropolymers in select high-temperature or chemical-exposed seals and hoses (usage is evolving due to regulatory scrutiny).
• Foams: Polyurethane (PU) foams in seats, NVH pads, and headliners; expanded polypropylene (EPP) for energy absorption and reusable packaging; melamine foams for acoustic insulation.
• Plastics in fuel and fluid systems: Multi-layer blow-molded tanks and lines with barrier layers (e.g., EVOH) to control permeation.

Because polymers are versatile and cost-effective, they are central to comfort, aerodynamics, and noise-vibration-harshness (NVH) performance, with recycling and bio-based content growing in importance.

Composites and lightweight solutions

Composites provide high specific stiffness and strength, enabling lightweight parts with tailored performance. They are used where weight savings justify higher materials and processing costs.

• Glass-fiber composites (GFRP): Common in springs, leaf-springs, bumper beams, seat structures, underbody shields, and exterior panels; made via injection, compression, or resin transfer molding.
• Carbon-fiber composites (CFRP): Applied in performance vehicles for roofs, hoods, tubs, and reinforcements; increasingly seen in selective mass-market parts where cost can be managed.
• Natural-fiber composites: Flax, hemp, kenaf reinforced polymers for interior panels and trims to cut mass and improve sustainability.
• Metal-matrix and sandwich structures: Aluminum honeycomb, fiber-metal laminates, and polymer-metal hybrids in local reinforcements and crash structures.

Automakers often pair composites with structural adhesives and mechanical fastening to create multi-material bodies that optimize mass, stiffness, and crashworthiness.

Glass, ceramics, and surface protections

Transparent, heat- and wear-resistant materials protect occupants, sensors, and surfaces, while coatings safeguard against corrosion and weathering.

• Automotive glazing: Laminated safety glass for windshields; tempered glass for side and rear windows; coatings for solar control, hydrophobicity, and defrosting; selective polycarbonate glazing in niche applications.
• Technical ceramics: Alumina and zirconia in spark plugs and oxygen sensors; piezo-ceramics in fuel injectors; ceramic substrates for catalytic converters and particulate filters.
• Coatings and treatments: E-coat primers, cathodic electrodeposition, powder/solvent-borne paints, galvanization (zinc), anodizing (aluminum), and PVD/CVD thin films for wear and appearance.

These materials enhance visibility, durability, emissions control, and aesthetics while protecting bodies and components against harsh environments.

Electronics and electrified powertrains

As vehicles become software-defined and electrified, electronic and electrochemical materials have become essential, from sensors to traction batteries.

• Semiconductors: Silicon for control units and sensors; silicon carbide (SiC) in traction inverters for high-voltage, high-efficiency EVs; gallium nitride (GaN) increasingly in onboard chargers and DC-DC converters.
• Conductors and dielectrics: Copper and aluminum busbars and wiring; high-temperature magnet wire; flexible printed circuits; EMI shielding materials; thermal interface materials (graphite, silicone pads, phase-change materials).
• Motors and magnets: Electrical steels for stator/rotor laminations; NdFeB permanent magnets (often with dysprosium or terbium for high-temperature stability) in many traction motors; ferrites in auxiliary motors.
• Battery materials (EVs and hybrids):
  – Cathodes: NMC/NCA (nickel-manganese-cobalt/nickel-cobalt-aluminum), LFP (lithium iron phosphate), and emerging high-manganese chemistries.
  – Anodes: Graphite with growing silicon-oxide/silicon content.
  – Electrolytes and separators: Organic carbonate electrolytes with LiPF6 salt; polyolefin separators; solid-state electrolytes under development (sulfides, oxides, polymers).
  – Enclosures and safety: Aluminum or steel battery enclosures, mica and ceramic insulators, flame-retardant foams.
• Charging and power distribution: High-voltage connectors, relays/contactors, fuses, and insulation systems rated up to 800+ V architectures.

These materials enable efficient power conversion, thermal management, and safety in modern vehicles, with SiC and LFP adoption expanding and sodium-ion batteries beginning limited deployment in some markets.

Fluids and consumables

Fluids reduce friction, manage heat, and transmit force, with formulations tailored for long life and compatibility with materials and emissions systems.

• Engine and e-axle lubricants: Multi-grade oils with additive packages; specialized e-fluids for electric drive units to manage dielectric strength and cooling.
• Coolants and thermal fluids: Water-glycol mixtures with corrosion inhibitors; dielectric coolants for batteries and power electronics in some designs.
• Brake and hydraulic fluids: DOT 3/4/5.1 glycol-ether fluids (and silicone-based DOT 5 in special cases).
• AdBlue/DEF (diesel exhaust fluid): Urea solution for SCR systems; fuel additives and transmission fluids tailored to specific gearboxes.

The right fluid chemistry prolongs component life and ensures performance across wide temperature ranges and duty cycles.

Interior materials and finishes

Occupant touchpoints prioritize comfort, safety, and emissions (low VOC), balancing durability with sustainability and premium feel.

• Textiles and leathers: Woven/knit fabrics, microfibers, genuine leather, and synthetic leathers (PU, PVC) for seats and trims.
• Foams and padding: PU seat foams with varying densities; energy-absorbing structures for head impacts.
• Decor and interfaces: Films, veneers, soft-touch coatings, and scratch-resistant finishes; optical-grade plastics for displays with anti-reflective and anti-fingerprint coatings.
• Adhesives and sealants: Epoxy, polyurethane, acrylic, and MS-polymer adhesives for assembly and NVH; butyl sealants for glazing and body seams.

Interior selections increasingly include recycled fibers, bio-based polymers, and low-emission adhesives to meet consumer expectations and regulatory requirements.

Joining and manufacturing processes

Material choice is inseparable from how parts are made and joined; modern vehicles mix processes to optimize performance and cost.

• Metal forming and casting: Stamping, hydroforming, roll-forming; aluminum high-pressure die casting (including large “gigacastings”); forging and extrusion.
• Plastics and composites fabrication: Injection molding, blow molding, compression molding, SMC, RTM, and filament layup.
• Joining techniques: Resistance spot welding, MIG/MAG and laser welding, brazing, riveting, clinching, flow-drill screws, and extensive structural adhesive bonding for multi-material assemblies.
• Additive manufacturing: Rapid prototyping and increasingly production of brackets, ducts, tooling, and complex metal parts with topology optimization.

The interplay between design, materials, and manufacturing enables lighter, safer vehicles with fewer parts and faster assembly.

Typical material mix by vehicle type

While every model differs, broad patterns illustrate how powertrain choices influence material proportions and where mass reduction is targeted.

• ICE vehicles: Often 55–65% steel by mass, 8–12% aluminum, 8–15% polymers and composites, 2–4% glass, 1–2% copper, with the remainder in elastomers and specialty metals. Cast iron remains common in engines and brakes.
• Battery electric vehicles (BEVs): More aluminum in bodies and subframes, much higher copper content (for motors, busbars, and cabling), and significant battery materials mass. Steel still features prominently in safety structures; composite usage varies by design. Total vehicle mass is often similar to or higher than ICE equivalents, but with mass redistributed to battery packs.

These mixes continue to shift as automakers adopt multi-material architectures, large aluminum castings, and lighter electrified drivetrains.

Sustainability, regulation, and sourcing trends (2024–2025)

Material choices are increasingly shaped by lifecycle carbon targets, recyclability, and supply security, with regulations and market forces accelerating change.

• Recycling and circularity: EU End-of-Life Vehicles rules target 95% recovery and 85% reuse/recycling by mass; design-for-disassembly and recycled polymers/metals are growing priorities.
• Battery regulations: New EU Battery Regulation phases in state-of-health tracking, recycled content, and recovery efficiency targets (e.g., minimum recycled cobalt, nickel, and lithium content by 2031, with higher thresholds by 2036), pushing closed-loop supply chains.
• Low-carbon metals: Increased use of electric-arc furnace (EAF) steel with high scrap content and pilot hydrogen-based DRI; more recycled aluminum in sheet and castings.
• Material substitutions: LFP cathodes expanding to cut cobalt and nickel dependencies; sodium-ion batteries piloted in select markets for cost and cold-weather resilience.
• Electronics efficiency: Wider adoption of SiC in inverters for 800 V platforms; GaN growth in onboard chargers for compact, efficient power conversion.
• Chemistry scrutiny: Interior VOC limits tightened; evolving restrictions on PFAS and microplastics influence sealants, coatings, and textiles, spurring alternative materials.
• Lightweighting methods: Advanced (Gen 3) AHSS, structural adhesives, and megacastings reduce parts count and mass while maintaining crash performance.
• Traceability and compliance: IMDS material declarations, responsible sourcing of critical minerals, and regional content rules guide material procurement.

These forces are driving a shift toward lower-carbon, recyclable, and regionally sourced materials without compromising safety or performance.

Key properties that drive material choice

Engineers select materials by matching properties to the job, balancing performance with manufacturability and cost.

• Mechanical: Strength, stiffness, ductility, fatigue, and impact energy absorption for crash and durability.
• Thermal: Heat resistance and conductivity for brakes, engines, motors, batteries, and thermal management systems.
• Chemical and environmental: Corrosion, UV, and fluid resistance for longevity and finish quality.
• Electrical and magnetic: Conductivity, dielectric strength, and magnetic properties for wiring, motors, and power electronics.
• Acoustic: Damping and insulation to manage NVH.
• Cost, mass, and sustainability: Tooling and process costs, lifecycle CO2, recyclability, and regulatory compliance.

The optimal choice is often a multi-material solution, with each component tuned to its local load case and environment.

Summary

Motor vehicles rely on a carefully engineered multi-material palette: steels and aluminum for structure; polymers, foams, and elastomers for comfort and NVH; composites for selective lightweighting; glass, ceramics, and coatings for visibility and protection; and, increasingly, sophisticated electronic and battery materials to power electrified drivetrains. As 2024–2025 models evolve, the mix is shifting toward lower-carbon metals, more recycled content, efficient semiconductors like SiC and GaN, and battery chemistries such as LFP—evidence that materials science now sits at the center of automotive performance, cost, and sustainability.

What material is a car motor made of?

An aluminum internal combustion engine is an internal combustion engine made mostly from aluminum metal alloys. Many internal combustion engines use cast iron and steel extensively for their strength and low cost. Aluminum offers lighter weight at the expense of strength, hardness and often cost.

What material is usually used to make the body of a car?

What are car bodies made of? Steel and aluminum are two of the most commonly used materials in the manufacturing of cars, mainly because both are strong metals.

Which material is used in automobiles?

Steel, rubber, plastics, and aluminum are the four most common commodities found in cars. The auto industry relies heavily on petroleum products, not just for gasoline for autos with internal combustion engines (ICE), but for synthesizing plastics and other synthetic materials.

What materials are used in modern cars?

The fact is that today’s vehicles are made from a staggering number of advanced materials: aluminum, high-strength steel, ultra-high-strength steel, boron, magnesium, carbon fiber, plastic, etc.