The largest auto assembly plant in the United States, explained

Tesla’s Gigafactory Texas outside Austin is currently the largest auto assembly plant in the U.S. by floor area, spanning roughly 10 million square feet; by designed annual vehicle capacity, Nissan’s Smyrna Vehicle Assembly Plant in Tennessee leads at about 640,000 vehicles per year. The distinction matters because “largest” can mean either physical footprint or how many vehicles a factory can build in a year.

By physical size: Tesla’s Gigafactory Texas

Tesla’s Austin-area plant, opened for production in 2022, is among the world’s biggest manufacturing buildings and the largest auto assembly site in the U.S. by floor area. The facility consolidates body, paint, general assembly and battery-related operations under one roof and builds the Model Y and Cybertruck. The complex’s footprint—publicly described by Tesla as on the order of 10 million square feet and more than a mile end-to-end—reflects Tesla’s vertical-integration strategy and ongoing expansion for high-volume EV production.

The list below highlights the key facts about Gigafactory Texas and why it ranks first by size.

• Location: Travis County (Austin), Texas
• Scale: Approximately 10 million square feet of floor area
• Products: Tesla Model Y and Cybertruck
• Status: Production launched in 2022; continuing ramp and expansions through 2024–2025
• Role: One of Tesla’s primary North American hubs for vehicle and battery-related manufacturing

Taken together, these details make Gigafactory Texas the largest U.S. auto assembly plant by physical footprint, even as its production volumes continue to scale.

By designed capacity: Nissan Smyrna Vehicle Assembly Plant

If “largest” is defined by how many vehicles a plant can produce annually, Nissan’s Smyrna facility in Tennessee remains the leader in the U.S. The site, in operation since 1983, has a stated capacity of roughly 640,000 vehicles per year and has long been among North America’s highest-volume auto plants. It has produced a range of models, including the Rogue, Pathfinder, and Infiniti QX60. While product mixes evolve—such as the phase-out of the Leaf to make way for future EVs—the plant’s scale and output capability continue to anchor its top ranking by capacity.

Below are key points that explain Smyrna’s capacity leadership.

• Location: Smyrna, Tennessee
• Designed annual capacity: About 640,000 vehicles
• Operational history: In service since 1983; repeatedly among North America’s highest-output plants
• Typical products: Nissan Rogue, Pathfinder; Infiniti QX60 (model mix varies over time)
• Footprint: On the order of 6 million square feet across a large multi-building campus

These factors help explain why, on a throughput basis, Smyrna is widely cited as the largest U.S. auto assembly facility by capacity.

Other very large U.S. auto plants to know

Several other assembly plants are notable for their size, output, or strategic importance. While they may not top both size and capacity simultaneously, they rank among the country’s largest by at least one key metric.

• BMW Manufacturing, Spartanburg (Greer), South Carolina: BMW’s largest plant globally; produces X-model SUVs; annual output commonly exceeds 400,000 units; a leading U.S. vehicle exporter by value.
• Toyota Motor Manufacturing, Kentucky (Georgetown): Among Toyota’s largest sites in North America; produces Camry, RAV4 Hybrid, Lexus ES; capacity generally in the ~500,000 range.
• Ford Kentucky Truck Plant (Louisville): Major producer of F-Series Super Duty, Expedition and Lincoln Navigator; one of Ford’s highest-volume truck/SUV plants.
• GM Arlington Assembly (Texas): Builds full-size SUVs (Chevrolet Tahoe/Suburban, GMC Yukon, Cadillac Escalade); among GM’s most profitable and high-output plants.
• Tesla Fremont Factory (California): Tesla’s original U.S. assembly site; multi-model production and significant output, though smaller footprint than Austin.

Each of these plants underscores how scale can be measured differently—by annual units, by square footage, or by economic impact via exports and product mix.

How “largest” is measured—and why it matters

In automotive manufacturing, “largest” can refer to several metrics: the building’s floor area, the plant’s designed annual capacity, actual yearly production, the acreage of the site, or its export value. Tesla’s Austin factory leads on floor space, signaling massive integrated operations and future growth. Nissan’s Smyrna plant leads on designed capacity, underscoring sustained high-volume throughput. Depending on which metric you prioritize, the “largest” label can legitimately apply to different facilities.

Summary

By size, Tesla’s Gigafactory Texas near Austin is the largest auto assembly plant in the United States. By designed annual capacity, Nissan’s Smyrna, Tennessee, facility holds the top spot. Both rankings are accurate—they simply use different definitions of “largest.”

What is the largest automotive manufacturing plant in the US?

While the term “largest” can refer to area or production, the BMW Manufacturing Plant in Spartanburg, South Carolina is the largest automotive exporter by value in the U.S., shipping over 225,000 vehicles in 2024, with an export value exceeding $10 billion. For a plant by square footage, the Toyota Manufacturing plant in Huntsville, Alabama is a massive engine plant covering 1.3 million square feet, producing more than 3,000 engines daily for a wide range of Toyota models. 
BMW Manufacturing (Spartanburg, SC) 

• Significance: It is the largest automotive exporter by value from the United States. 
• Output: The plant produces BMW Sports Activity Vehicles and Coupes, exporting the majority of its production. 
• Economic Impact: In 2024, the plant exported over $10 billion worth of vehicles. 

Toyota Manufacturing (Huntsville, AL) 

• Significance: This facility is a major engine production hub, responsible for about one-third of Toyota’s engine output in the U.S.
• Capacity: It produces over 3,000 engines daily for models like the Corolla, Highlander, and RAV4.
• Infrastructure: The plant sits on a large, 1.3 million square-foot campus.

Who is the largest auto manufacturer in the United States?

General Motors (GM)
1. General Motors (GM) – 17% Market Share. General Motors remains the largest automaker in the U.S., thriving by investing early in electric vehicles and digital operations.

Who assembles the most cars in the US?

Ford assembles more vehicles in the U.S. than any other manufacturer. Ford assembled more than 1.8 million vehicles in the U.S. last year – 130,000 more than any other auto manufacturer.

Who is bigger, GM or Ford?

No, General Motors (GM) is not smaller than Ford; GM is the larger automaker based on recent production and market share, though Ford is a significant competitor. While both are considered the U.S. “Big Three,” GM consistently sells more vehicles than Ford and had higher total assets and more employees as of 2024. 
Here’s a comparison:

• Vehicle Production: Ford is the second-largest American automaker, but General Motors produces more vehicles globally. 
• Employees & Assets: As of 2024, GM had 162,000 employees and $279.8 billion in total assets, indicating a larger operational scale than Ford, according to Wikipedia. 
• Market Share: GM holds a larger market share in the U.S. automotive industry compared to Ford. 
• History: Although Ford is a massive company, GM has historically held a lead in size, a position that has been maintained over time despite global shifts in the industry.