What material is a car body made of?

Most modern car bodies are primarily made of steel—especially high-strength and advanced high-strength steels—supplemented by aluminum panels and castings, with selective use of plastics and fiber-reinforced composites; premium and performance models may use aluminum-intensive bodies or carbon fiber, and a few niche vehicles employ stainless steel. In practice, automakers mix materials to balance safety, weight, cost, manufacturability, and repairability, so the exact recipe varies by model and segment.

The core materials in modern car bodies

The “body-in-white” (the welded structural shell before paint) in mainstream vehicles still relies heavily on steel, now in far tougher and lighter grades than in decades past. Outer closures (hoods, doors, trunk) and some substructures increasingly use aluminum to trim weight. Plastics and composites form many exterior trims and, in some cases, body panels. A few specialized vehicles push further, using carbon fiber or even stainless steel.

Below is a breakdown of the most common materials you’ll find in car bodies today, along with what they’re used for and why.

• Advanced high-strength steels (AHSS) and press-hardened steels (PHS): Form the safety cage, pillars, rails, and crash structures; deliver high crash performance with thinner gauges and are cost-effective at scale.
• Mild and high-strength low-alloy steels (HSLA): Used where extreme strength isn’t essential—floor pans, brackets, and some panels—offering good formability and low cost.
• Aluminum sheet (5xxx/6xxx series): Common for hoods, fenders, doors, and liftgates; reduces mass while maintaining dent resistance (6xxx bake-hardened grades are typical for outer panels).
• Aluminum castings and extrusions: Structural nodes, shock towers, subframes, and, increasingly, large “megacastings” (e.g., rear/front underbody sections) that simplify assembly and cut weight.
• Magnesium (limited use): Lightweight cast components like instrument panel supports or small brackets; less common for exterior body panels due to corrosion and cost.
• Plastics and composites: Thermoplastic bumpers and fascias, SMC/fiberglass body panels on some performance cars, and carbon fiber reinforced polymer (CFRP) for roofs, hoods, or entire passenger cells in niche models.
• Stainless steel (rare): Employed as an exterior skin on a few vehicles (e.g., Tesla Cybertruck) for dent resistance and distinctive styling; more difficult to form and repair, and heavier than aluminum.
• Adhesives and sealers (joining materials): Structural adhesives and sealers are integral to modern multi-material bodies, improving stiffness, crash energy management, and corrosion protection.

Taken together, these materials create a “right material, right place” structure: steel dominates for crash-critical geometry, aluminum removes weight where feasible, and composites or specialized metals appear where they deliver a clear advantage.

Why automakers mix materials

Engineers select materials to meet regulations and customer expectations while controlling cost and complexity. The trade-offs are predictable but non-trivial.

1. Crash safety and stiffness: Strong steels and bonded joints maintain cabin integrity and tune crash energy absorption.
2. Weight and efficiency: Aluminum and composites cut mass, improving fuel economy and EV range without sacrificing performance.
3. Cost and manufacturability: Steel is affordable and easy to stamp; aluminum and composites can add cost and require different tooling.
4. Corrosion and durability: Galvanized steels, e-coat, and careful joining mitigate corrosion; aluminum resists rust but can galvanically corrode if poorly joined to steel.
5. Repairability and insurance: Aluminum, ultra-high-strength steels, stainless, and composites need specialized repair methods, affecting repair costs and total cost of ownership.

The result is not a single “best” material but a tailored mix that meets the vehicle’s mission—city car, pickup, luxury sedan, or supercar—at a viable price.

Real-world examples across the market

The following examples illustrate how different models deploy materials to hit their targets for safety, weight, cost, and performance.

• Ford F-150 (2015–present): Aluminum body panels (hood, doors, bed, etc.) over a high-strength steel ladder frame, cutting weight while preserving towing and payload.
• Tesla Model S/X: Aluminum-intensive bodies to maximize weight savings; Tesla Model 3/Y use a mixed steel-aluminum body with large aluminum castings (rear, and on some builds front) plus aluminum closures.
• Tesla Cybertruck: Cold-rolled stainless steel exterior “exoskeleton” skins combined with a structural battery pack—trading ease of forming for dent resistance and distinctive aesthetics.
• Jaguar and Land Rover (e.g., XE, XF, Range Rover): Aluminum-intensive body-in-white strategies for weight reduction in premium segments.
• Audi A8 (D5): Multi-material body with extensive aluminum, high-strength steel in critical areas, magnesium components, and CFRP for the rear panel to fine-tune stiffness and mass.
• BMW 7 Series (G11/G12): “Carbon Core” uses CFRP in pillars and roof rails within a mixed-metal structure; BMW i3 pioneered a CFRP passenger cell over an aluminum frame.
• Chevrolet Corvette (C8): Composite outer panels (SMC/fiberglass) over an aluminum space frame; optional carbon fiber for select parts.
• Mainstream sedans and crossovers (e.g., Toyota Corolla, Honda Civic): Predominantly AHSS/PHS steel shells with aluminum hoods or liftgates to trim mass cost-effectively.

These cases show that while steel remains the backbone for most vehicles, aluminum and composites are strategically deployed where they deliver the best return on weight, performance, or styling.

EV trend spotlight

Battery mass has pushed EVs toward more aluminum and cast structures, but ultra-high-strength steels remain essential for the occupant cell. Battery enclosures themselves are becoming a notable part of the “body” mix.

Here are common battery enclosure material strategies and why they matter.

• Aluminum extrusions and castings: Favorable stiffness-to-weight, good thermal conductivity, and corrosion resistance; common in many EV packs.
• Steel enclosures: Cost-effective with excellent crash performance; often used when underbody protection is prioritized and mass targets permit.
• Composite enclosures (SMC/CFRP hybrids): Emerging for weight savings and integrated flame/thermal barriers, with growing adoption as costs decline.

As structural battery packs integrate with the body, the line between “body” and “battery enclosure” blurs, accelerating multi-material design and new joining techniques.

Surface protection and joining techniques

Most steel body shells are zinc-coated (galvanized or galvannealed) and then electro-coated (e-coat) before paint to combat corrosion. Aluminum panels often receive conversion coatings and sealants to prevent galvanic issues where they meet steel. Joining is likewise multi-modal: resistance spot welding and laser welding for steels; self-piercing rivets, flow-drill screws, structural adhesives, and, in some cases, friction stir welding for aluminum. Mixed-material joints rely heavily on adhesives and mechanical fasteners to maintain strength and durability while preventing corrosion.

Repair and ownership implications

Material choices affect repairability and insurance costs. Ultra-high-strength steels can’t be straightened with heat without compromising strength; aluminum body repair needs dedicated tools and isolation to prevent cross-contamination; stainless skins may be more dent-resistant but harder to refinish; composites often require replacement or specialized layup repairs. Owners should consult OEM repair procedures to ensure safety systems remain within spec after a crash.

Environmental and recycling considerations

Steel is widely recycled with mature, efficient infrastructure, and modern grades reduce lifetime emissions via weight savings. Aluminum recycling saves substantial energy versus primary aluminum and is well-established in the auto industry. Composite recycling is improving but remains less mature; thermoplastic parts are easier to recycle than thermoset composites. Automakers increasingly design for disassembly and material separation to hit sustainability targets.

How to find what your car uses

If you want to know exactly what your vehicle’s body is made from, these steps will point you to authoritative sources and easy at-home checks.

1. Check the owner’s manual and OEM brochures: Many list aluminum closures or composite components explicitly.
2. Consult OEM service and body repair manuals: They map material grades (e.g., 980 MPa, PHS) and specify joining/repair methods.
3. VIN-based parts catalogs and build sheets: Dealer systems and some third-party tools reveal panel material and supplier details.
4. Automaker press kits and engineering white papers: Often detail multi-material strategies for new generations.
5. Simple tests: A magnet won’t stick to aluminum or most stainless panels; weight and sound can distinguish steel from composites.

Together, these sources provide a clear picture of your car’s material makeup, and the repair manual guidance helps ensure safe maintenance.

Summary

Car bodies today are multi-material structures: steel—especially advanced high-strength grades—still does most of the heavy lifting, aluminum cuts mass in panels and cast substructures, composites and plastics fill targeted roles, and stainless steel appears in rare, distinctive designs. The precise blend varies by model and mission, balancing safety, efficiency, cost, manufacturability, and repairability. If you’re curious about a specific vehicle, OEM repair documentation and press materials offer the most accurate, up-to-date breakdown of its body materials.

What is the exterior of a car made of?

A car’s exterior is made of a combination of materials, with steel and aluminum being the most common for body panels and the underbody. Modern cars also incorporate plastics for components like bumpers and fascias, as well as other metals such as magnesium and carbon fiber in higher-end models for weight reduction and improved performance. The specific combination of materials varies depending on the vehicle’s design, cost, durability, and performance goals.
 
Common Materials

• Steel: Opens in new tabA strong, accessible, and cost-effective material that has been the primary material for car bodies for decades. High-strength and ultra-high-strength steels are often used in the unibody frame. 
• Aluminum: Opens in new tabA lightweight, corrosion-resistant metal used in many body panels, such as hoods and decklids, to reduce vehicle weight and improve fuel efficiency. 
• Plastics: Opens in new tabUsed for parts like bumpers and fascias, plastics offer durability and can be molded into various shapes. 
• Carbon Fiber: Opens in new tabFound in some higher-end vehicles, carbon fiber is a strong, ultra-lightweight material used for unibody construction to significantly reduce weight and boost performance. 
• Magnesium: Opens in new tabAn emerging option, magnesium is one of the lightest structural metals, though its high cost and manufacturing complexities currently limit widespread use. 

Why the Mix of Materials?

• Weight Reduction: Lighter materials like aluminum and carbon fiber contribute to better fuel efficiency. 
• Performance: Lightweight materials improve overall vehicle performance. 
• Cost-Effectiveness: The use of steel, a relatively inexpensive material, helps control manufacturing costs. 
• Durability and Corrosion Resistance: Modern cars often use galvanized steel and aluminum to prevent rust, which was a more significant issue with older steel bodies. 
• Design Flexibility: Plastics allow for complex shapes and designs, especially for bumpers and other external features. 

When did cars stop being made of metal?

Cars never completely stopped being made of metal; rather, metal became a material alongside plastic, aluminum, and other materials, rather than the sole primary component. While the industry shifted toward mass production of steel-bodied cars in the early 20th century, the use of other materials like plastic increased significantly from the mid-20th century onwards to reduce weight, improve fuel efficiency, and meet emissions standards.
 
History of Metal in Cars

• Early 20th Century: The introduction of the first all-steel-bodied automobile in 1914 by Dodge marked a major shift, with steel bodies becoming the standard by the late 1930s. 
• Mid-20th Century: Steel continued to be the primary material for car chassis and bodies through the early 1970s and beyond. 
• Late 20th Century: Despite the prevalence of steel, there was also a shift towards using more aluminum for bodies to improve fuel economy. 
• Modern Cars: Today, cars are made from a combination of materials, including steel, plastic, aluminum, rubber, and glass. 

Reasons for Material Diversification 

• Weight Reduction: The use of plastic and aluminum in vehicles helps to reduce overall weight.
• Fuel Efficiency: Lighter vehicles require less fuel, improving fuel economy.
• Emissions Standards: Reducing fuel consumption also leads to lower emissions, helping manufacturers meet stricter environmental regulations.

What material are most car bodies made of?

Car bodies today are most commonly made of steel and aluminum, with steel remaining a cost-effective choice for mass-produced vehicles. Aluminum is increasingly used for its lightweight properties, which improve fuel efficiency, particularly in larger vehicles. For higher-performance or more expensive sports cars, bodies can be made from strong but costly carbon fiber. Additionally, lightweight magnesium alloys are used for specific components, and various types of plastic are used for other parts like front and rear panels. 
Key materials and their uses:

• Steel: Opens in new tabRemains the traditional and most widely used material due to its strength, durability, and low cost. 
• Aluminum: Opens in new tabBecoming the material of choice for its lighter weight and corrosion resistance, used in components like hoods and liftgates. 
• Carbon Fiber: Opens in new tabA very strong and lightweight material, but its high cost restricts its use to high-end or specialty vehicles. 
• Plastic: Opens in new tabUsed extensively for various parts, including front and rear panels and other trims. 
• Magnesium Alloys: Opens in new tabLightweight magnesium is increasingly used for certain body components. 

Why the different materials are chosen:

• Cost: Steel is the most economical choice for most vehicles. 
• Weight: Aluminum and carbon fiber help reduce vehicle weight, leading to better fuel efficiency and performance. 
• Strength and Safety: All materials are chosen to meet strict safety standards, with different steels and other materials providing varying levels of crash protection. 
• Corrosion Resistance: Aluminum and certain steel treatments are important for protecting against rust. 

What is the most common vehicle construction material?

Steel (Iron Ore)
Steel is produced from iron ore and is traditionally widely used in auto manufacturing. On average, 900 kilograms of steel are used in every car. Steel is used to construct a car’s chassis and body, including the roof, body, door panels, and the beams between doors.