Transportation Equipment Manufacturing (United States) — NAICS 336

A Histometrics rollup primer for public-market and private investors.

What this page is. NAICS (North American Industry Classification System — the standard the U.S. government uses to group businesses) code 336 is a three-digit subsector: the factories that build things that move people and freight — on roads, in the air, on rails, and on water. It sits one rung above seven four-digit industry groups: motor vehicles (3361), vehicle bodies and trailers (3362), motor-vehicle parts (3363), aerospace (3364), railroad rolling stock (3365), ships and boats (3366), and an "everything else" bin (3369). This primer's job is the contrast across the seven — how big each is, which way each is heading, who owns them, and how you invest — and then the subsector as a whole. For company-by-company detail, drop into any child primer.

The seven children have been rebuilt on independent company-level sourcing — SEC filings, foreign annual reports, trade-association data, and federal series newer than the 2022 census. This page now carries measured margins across all seven, a materially changed trade and emissions picture, a reshuffled roster of listed companies, and several corrections the earlier version got wrong.

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1. Overview

NAICS 336 is the single largest slice of American advanced manufacturing: roughly $1.02 trillion in annual shipments and 1.68 million workers across ~11,700 plants [1]. It is where the country builds the physical machinery of movement — cars and pickups, the trucks and trailers that haul freight, the parts that go inside all of them, jetliners and fighter jets, railcars and locomotives, warships and pleasure boats, tanks, motorcycles, and snowmobiles.

The single most useful fact about this subsector is that it is not one industry but a portfolio of three loosely connected economies stapled together by a shared skill — bending metal and assembling complex vehicles. Sort the seven children by what actually drives their sales and they fall into three buckets:

• A giant consumer-vehicle complex — cars and light trucks (3361), their parts (3363), plus the recreational slices of bodies/trailers (3362), boats (3366), and powersports (3369). This is by far the biggest piece and answers to households, interest rates, and the auto cycle.

• A freight-and-industrial layer — heavy trucks, freight trailers, railcars and locomotives, and the aftermarket that keeps them running. This answers to freight — how much cargo is moving — and to construction.

• A government-and-defense spine — military aircraft and missiles (inside 3364), warships (inside 3366), and armored vehicles (inside 3369). This answers to the federal budget and geopolitics, not to consumers at all.

Because those three engines run on different clocks, the subsector as a whole is far steadier than any one child. A consumer recession that guts car and boat sales barely touches a submarine program or a tank line; a freight downturn that idles trailer plants does nothing to a jetliner backlog. That built-in diversification — not any single headline number — is the first thing an investor should carry away.

What the revised children change. Three things, and they matter more than any single figure. First, the three engines are themselves subdividing: the children now document splits inside each half that the old two-way framing missed — motorhomes rising 11.8% while towables fell 17.2% in the same five months of 2026 [3], and heavy ground-armor procurement drifting down while shipbuilding and munitions climb [5][8]. Second, margins now sort by defensibility rather than by product category, and the widest gaps sit inside a single child, not between children (§5). Third, the trade picture hardened: the U.S.-Mexico-Canada Agreement (USMCA) was not extended in its current form at the scheduled July 2026 review, leaving the cost base of the subsector's most cross-border child genuinely unsettled [4][12].

One-line takeaway. A $1 trillion advanced-manufacturing subsector that is ~72% automotive by revenue, anchored on the other side by the world's strongest aerospace-and-defense export base — seven oligopolies with almost no overlapping leaders, which is why the whole thing looks deceptively un-concentrated (§8).

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2. What's inside — the seven children and how they differ

NAICS 336 contains seven four-digit industry groups. Two of them (3361 motor vehicles, 3363 parts) are themselves real rollups with multiple children; the other five are single-industry "pass-throughs" that only fan out one level lower, at the six-digit detail. Ordered largest to smallest by U.S. shipments:

Shares are of the subsector's $1,023.7B receipts and 1,682,910 jobs [1]; the direction-of-travel figures come from the children [2–8]. ADR = American Depositary Receipt (a foreign share wrapped to trade on U.S. exchanges); PE = private equity; A&D = aerospace and defense; Tier-1 = a supplier that sells finished systems straight to the manufacturer; ETF = exchange-traded fund (a fund that trades like a stock); EV = electric vehicle.

The contrasts worth internalizing:

1. Autos dominate the money; parts and aerospace dominate the jobs. The three automotive children (3361 + 3362 + 3363) are ~72% of receipts and ~62% of employment — the subsector's center of gravity is unmistakably the car economy [1]. But rank by headcount and the order flips: parts (3363) is the biggest employer (587k), then aerospace (429k), with vehicle assembly (3361) only third (277k) despite being #1 in revenue.

2. Capital-intensity varies enormously — read it in revenue per worker. Auto assembly (3361) throws off ~$1.4 million of shipments per worker — a handful of highly automated mega-plants; ship and boat building (3366) manages roughly $310,000 per worker — labor is the product. That ~4.5× gap is why the two pay their people so differently (see below) and why they behave so differently in a downturn.

3. Pay tracks capital-intensity and technology. Average pay runs ~$111,000 in auto assembly and ~$108,000 in aerospace, ~$88,000 in rail, and ~$59,000–$69,000 in the labor-intensive consumer children — bodies at ~$59,000, parts ~$62,000, powersports/armor ~$67,000, boats and ships ~$69,000 [2–8]. The subsector average is ~$83,000 [1]. Inside 3369 the ladder repeats in miniature: ~$53,000 in motorcycles and bicycles, ~$68,000 in powersports, ~$75,000 in the clearance-intensive armored- vehicle plants [8].

4. Almost every child is itself two businesses — and the revised children show it goes finer than that. Motor vehicles = a consumer car business + a freight truck business. Aerospace = commercial (air travel, ~82% of the level) + defense/space (~18%) [5]. Ship/boat = Navy warships (~64% of receipts from ~35% of the plants) + consumer pleasure boats (~36% of receipts across ~65% of the plants) [7]. But bodies/trailers is now explicitly four cycles, not two — truck bodies, freight trailers, motorhomes, and towables diverged sharply in a single five-month stretch [3]; parts sorts its eight children into EV winners, EV losers, and powertrain-agnostic neutrals rather than two halves [4]; and 3369 is three unrelated worlds whose leaders never overlap [8]. The subsector is a fractal of paired opposites, but the pairs subdivide — which is exactly why owning breadth here diversifies, and why a single child is never a single exposure.

5. Trade posture splits the subsector in two — and the split hardened. Aerospace (3364) runs the largest trade surplus of any U.S. manufacturing sector — aircraft and spacecraft exports of roughly $134 billion in 2024 and an A&D trade surplus on the order of $109 billion in 2025 [5][9]. The auto complex (3361/3363) runs the other way: a net importer, with much of its assembly and its labor-intensive parts work done in Mexico and Canada. That exposure is now unhedged: at the scheduled July 2026 review the administration declined to extend USMCA in its current form, leaving the rules governing the complex's cross-border footprint unresolved [4][12]. So NAICS 336 contains both America's export champion and its most tariff-exposed cyclicals in the same box.

For product scope, exclusions, and company tables, follow any child link (3361 vehicles, 3362 bodies/trailers, 3363 parts, 3364 aerospace, 3365 rail, 3366 ship/boat, 3369 other).

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3. How big it is (this level's rollup figures)

These are our ground-truth federal statistics for NAICS 336 as a whole. Reassuringly, the seven children add up almost exactly to the subsector totals — a strong sign the data is internally consistent [1–8]:

The one figure that does not sum cleanly is firms: the seven children's firm counts total ~9,595 against the subsector's 9,473. The ~122 gap is diversified companies — a Magna, a BorgWarner, a General Dynamics — that operate in more than one industry group and are counted once at the subsector level but appear in several children. The same arithmetic repeats one level down and is worth reading as a structural signal rather than a rounding error: parts shows a ~200-firm gap across its eight children, aerospace a ~67-firm gap across six, and 3369 a gap of just three across its three — the last of which is the numerical proof that almost no company in that bin competes in more than one of its markets [4][5][8].

Undercount caveat — it runs backward here. Many industries are undercounted because tiny or informal operators slip past the Census. Transportation equipment is the opposite: a corporate, plant-based, payroll-filing field dominated by large, well-captured firms, so small/individual ownership is not a gap. The direction of error is understatement of the true economic footprint, not of firm count, and it comes from five sources:

• Cross-border assembly. Much North American vehicle and railcar assembly happens in Mexico and Canada, outside U.S. counts — Greenbrier and Trinity both run large Mexican plants — so the U.S. footprint of the auto and rail economies is larger than these figures show [2][4][6].

• Imports. The U.S. consumes far more than it makes, and in the smaller consumer children the gap is close to total: roughly 97–99% of bicycles sold here are imported, and about 99% of assembled golf carts imported in 2024 came from China [8]. In brakes, ~$10.2 billion of domestic shipments sits against an estimated $22–26 billion of U.S. consumption [4]; trailers show the same wedge, which is what drives the 2026 trade case [3]. Domestic production understates the size of the underlying markets everywhere in the auto complex.

• The fattest profit pools sit in other codes. Replacement parts, captive vehicle financing, and equipment leasing — the steadiest money in this subsector — are booked under non-336 NAICS codes (railcar leasing under 532411, for example) [6]. Aerospace's satellites (334220) and much missile/space work (booked as R&D, 541715) are likewise carved out; the Census sizes the whole U.S. space economy at $142.5 billion of GDP in 2023, and industry associations size the full A&D value chain near $850 billion, several times the $203.5B counted here [5][9].

• Captive production is filed with the vehicle, not the part. Census classifies a plant by its primary product, so work a company does for its own vehicles usually lands with the vehicle: automakers stamp body panels and build engines in-house under 336110/336111 rather than under parts, and SpaceX and Blue Origin build rocket engines in volume but are classified with launch vehicles rather than propulsion [4][5]. Every figure in the parts and propulsion children is therefore a floor on the underlying activity, and the boundaries move volume between children when companies reorganize — Boeing's reabsorption of Spirit AeroSystems in December 2025 pulled roughly 15,000 workers and a large block of structures work back inside an airframer [5].

• Public naval shipyards. The four government-owned yards that maintain the Navy's nuclear fleet (~37,000 federal civilian workers) are excluded from these private-sector statistics — true national ship-and-boat-building employment is closer to ~185,000 than the ~150,600 counted here [7].

A caveat the revised children add: establishment counts overstate the number of real manufacturers. Plant counts and firm counts are not a census of who can actually build the product. The Federal Railroad Administration states that only six manufacturers build new freight railcars, against 220 establishments classified in 3365 — and concluded that the NAICS distribution is not a reliable description of new-car manufacturers [6]. The GAO counts seven builders of Navy battle-force ships in the entire country, against 1,427 ship-and-boat establishments [7][15]. On the car side, the Alliance for Automotive Innovation counts 20 automakers operating 55 light-vehicle assembly plants in 15 states, against 222 Census establishments in the car child [2][10]. The gap is definitional rather than an error — use Census figures for statistical comparison and industry counts when you mean physical capacity — but it means the plant column in §2 cannot be read as a measure of competitive depth.

No values in the table above are suppressed. Suppression is common one and two levels down, however, and it is itself a concentration signal rather than a data gap: the level HHI is withheld for ship/boat (3366), for heavy trucks (336120), for motorcycles and bicycles (336991), and for four of aerospace's six detail industries — in each case because so few firms operate that publishing an index would effectively disclose individual companies [5][7][8]. Where a number is suppressed we state none, and read the disclosed CR4/CR8 ratios instead.

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4. Investable universe — where value concentrates across the children

The defining fact of this level: there is no single stock, and no single ETF, that is "NAICS 336." You assemble exposure child by child, and where value concentrates differs sharply by child. Four patterns cover the whole board:

• A handful of very large anchors span several pieces at once. The diversified names recur across the table: in aerospace/defense, Boeing, GE Aerospace, RTX, Lockheed Martin, Northrop Grumman, General Dynamics — the last of which alone spans warships and armored vehicles, with Marine Systems at ~$16.7 billion and Combat Systems at ~$9.2 billion of 2025 revenue [7][8]; in parts, Magna, BorgWarner, Aptiv, Dana. Buying one of these buys a weighted basket of the subsector.

• Clean, listed pure-plays exist only in patches — and the patchwork moved. You can still own a car business cleanly (GM, Ford, Tesla), a heavy-truck maker cleanly (PACCAR), an RV maker cleanly (Thor, Winnebago), a freight-car maker cleanly (Greenbrier, Trinity), and a powersports maker cleanly (Polaris, BRP). The parent's old claim that motor-vehicle parts has no clean U.S.-listed pure-play is now wrong: three of the eight parts children have one — transmission (Allison, Dana, and Dauch, the renamed American Axle after the Dowlais combination closed in February 2026), seating (Adient, Lear), and, since April 1, 2026, electrical wiring via Versigent, spun out of Aptiv — with ITT a partial fourth in brake friction [4]. Truck bodies and aircraft/missile propulsion remain without one, though L3Harris's solid-rocket-motor carve-out is expected to list in the second half of 2026 [5].

• The richest public menu is still in aerospace parts and the aftermarket. Aircraft-parts specialists and aftermarket compounders (TransDigm, HEICO, Loar, Howmet, Hexcel, Woodward, Curtiss-Wright, Moog) offer regulation-protected, installed-base economics that trade at premium multiples — the highest-quality corner of the subsector for public investors [5].

• The private and foreign-owned majority is where most of the tonnage actually trades hands. Across parts, truck bodies, propulsion, transit railcars, mid-tier shipyards, and bicycles, ownership is dominated by foreign Tier-1 suppliers, private equity, and family holders. Private capital is a first-class owner of this subsector, not a fringe — Apollo (Tenneco, Barnes Group), KKR (Marelli), Warburg Pincus and Berkshire Partners (Triumph), AE Industrial (Aerojet's space-propulsion arm), Platinum Equity (Club Car), Carolwood (Indian Motorcycle), and the buyers rolling up the fragmented truck-body and aerospace-supplier tails [3][4][5][8].

The listed roster is diverging, and it is worth watching as a trend rather than a list of trades. Aerospace and parts gained public exposure over 2025–26 — SpaceX listed in June 2026, Karman is a clean missile/space-parts play, Versigent separated from Aptiv, AUMOVIO from Continental [4][5]. The consumer-cyclical children lost it: REV Group disappeared into Terex in February 2026, Marine Products into MasterCraft in May 2026, Indian Motorcycle went to private equity in February 2026, and Textron announced in April 2026 that it intends to separate its whole Industrial segment, E-Z-GO included [3][7][8]. Public money is consolidating toward the A&D spine and the parts base while the consumer half goes private.

For private investors specifically, note that direct ownership of a final assembler — a car plant, an airframer, a shipyard — is rare in every child; the assets are too capital-intensive and strategically sensitive. Private capital sits around the assembler: parts and component suppliers, aftermarket and remanufacturing roll-ups, dealer and service groups, leasing and rental fleets, and venture stakes at the EV/battery/charging, electric-air-taxi, and commercial-rocket frontiers. Tickers, scale figures, and multiples belong with those specific names — see §10 and each child primer.

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5. How the money works

Beneath seven different products, one financial skeleton travels across the whole subsector, plus one recurring escape hatch:

• It is high-fixed-cost, cyclical assembly — and most of the value is purchased, not made. An owner earns the spread between a vehicle's price and its build cost, times volume, minus enormous fixed costs for plants, tooling, and skilled labor. Those fixed costs don't flex, so capacity utilization is the swing factor — Trinity's Rail Products segment earned a 5.2% operating margin at roughly 50% utilization in 2025, against Greenbrier's 14.5% [6]. The children now also quantify how thin the manufacturing slice really is: bought-in content runs at roughly two-thirds of GM's automotive cost of sales, ~85% of a new PACCAR truck's cost, more than 70% of most railcars' cost, and 66% of Allison's cost of sales [2][4][6]. NAICS 336 is the final-assembly slice of value chains filed mostly under other codes — which is why operating leverage here is so violent in both directions.

• The manufacturing is the low-margin part; the annuity beside it is where steady money hides — and it is now measured, not asserted. This is the single most important economic pattern in the subsector, and it repeats child by child. New-jet sales are thin — Boeing's commercial unit ran a −17.1% operating margin in 2025 — but engine services generated $25.0 billion of GE Aerospace's $33.3 billion commercial segment at a 26.6% margin [5]. New-railcar margins are thin, but Wabtec's Freight segment earned 19.5% with 58% of sales from aftermarket work on an installed base of ~24,600 locomotives [6]. New-trailer assembly lost money — Wabash's trailer gross margin collapsed from 12.4% to 1.9% — while its Parts & Services arm earned 18.6% [3]. New-truck margins are thin, but PACCAR Parts turned over $6.67 billion, about 24% of company revenue, and PACCAR Financial financed 27.0% of new truck sales [2]. Harley-Davidson makes the point most starkly: its motorcycle segment posted a $29 million operating loss in 2025 while the company earned $339 million of consolidated net income, on the strength of its credit arm [8]. Unhelpfully for anyone reading NAICS 336 in isolation, most of that annuity is booked in other codes.

• Two children break the mold on the government side — but the familiar framing inverts at a trough. Warships and military aircraft/missiles run on long-cycle government contracting: revenue booked over years against an estimate of total cost (a rising estimate triggers an immediate profit charge — HII recorded $350 million of unfavorable cumulative catch-up adjustments in 2025), mid-single-digit margins, and profit that turns on throughput rather than open-market price [7]. The conventional read is that this is the dull, thin-margin half. In 2025 it was not: Brunswick's Boat segment ran a 2.1% GAAP operating margin, below Newport News' 5.1% and less than a third of General Dynamics Marine Systems' 7.0% [7]. Fixed-price defense risk is chronic and bounded; consumer operating leverage is acute and unbounded. Any comparison of the two halves has to say where in the cycle it is standing.

• Margin dispersion sorts by defensibility, not by product category — and it is widest inside a child. This is the sharpest new finding at this level. Allison earns a 37.5% adjusted EBITDA margin while Dana earns 8.1%, both inside the same parts child — a 29-point gap between a protected commercial-truck franchise with multi-year agreements and contested light-vehicle driveline work [4]. Rail repeats it (Wabtec 19.5% against Trinity 5.2%), bodies repeat it (Thor's towable segment at a 13.1% gross margin against Winnebago's motorhome segment at a −0.6% operating margin), and ship/boat repeats it across the defense/consumer line [3][6][7]. There is no "industry margin" at any level of NAICS 336. Read the number as evidence about a specific franchise's defensibility, never as a category average.

• Content and mix are the only growth levers when unit volumes are flat. Selling more dollars per vehicle — more electronics per car, a premium seat, a heated-and-ventilated cabin, a bigger engine — lets the best suppliers outgrow a stagnant unit market. Electronic content is projected toward 35–40% of total vehicle value by 2035 [4]. This "content per vehicle" story is what separates winners from losers inside parts and aerospace alike.

The dials to watch across the subsector: capacity utilization, backlog/book-to-bill, original- equipment-versus-aftermarket mix, margin net of commodity (steel/aluminum) pass-through, and free cash flow against debt. Treat backlog as a softer number than it looks — RV dealer orders can often be cancelled without penalty, commercial customers may change quantity or timing, and the Navy can cancel a program outright [3][7]. Regulated-utility rate base, real-estate funds-from-operations, and mining all-in-sustaining-cost yardsticks do not apply here.

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6. Demand drivers

Because the subsector is three economies (see §1), it runs on three master demand engines, and the whole point of NAICS 336 is that they rarely peak or trough together:

• The consumer/discretionary engine (biggest). Household spending, jobs, interest rates and financing affordability (most vehicles, boats, and RVs are financed — and dealer inventory is "floor-plan" financed, so higher-for-longer squeezes buyer and dealer at once), consumer confidence, and long replacement cycles. The floor is the installed fleet: ~289 million U.S. light vehicles at a record average age of 12.8 years, a durable, recession-resistant tailwind under the parts aftermarket [4]. The 2025–26 evidence shows this engine is not one signal but several: new light-vehicle sales rose ~2.4% to 16.2 million units, while powerboat retail units fell 8.8% to 215,237, RV shipments fell 14.4% through May 2026 (motorhomes up 11.8%, towables down 17.2%), and worldwide snowmobile retail fell from roughly 125,000 units two seasons earlier to about 90,000 [2][3][7][8]. Policy can move it violently: the federal EV purchase credit expired September 30, 2025, spiking battery-EV share to a record 12% that month before it fell below 6% for the rest of the year [2].

• The freight/industrial engine. Freight volumes and carrier profitability, construction and vocational work, carloadings, and regulatory "pre-buys" (fleets ordering ahead of a costly new emissions rule). The 2023–25 freight recession cut orders hard across all three freight children in the same direction: heavy-truck retail fell ~13% in 2025 with ACT Research projecting roughly 171,000 Class 8 units in 2026 (down ~18%); U.S. trailer output fell to 200,485 units from 245,344, with the entering-2026 backlog ~21% lighter; and railcar orders fell to 20,361 from 60,734 in 2022 [2][3][6]. One caution the rail child adds and the others echo: order boards are not clean leading indicators — they have to be decomposed into regulatory pull-forward, cancellations, and genuine expansion, and better utilization can absorb traffic growth before it reaches a factory.

• The government/defense engine — up in aggregate, but reallocating underneath. The U.S. defense topline runs near $839 billion for fiscal 2026, and the Navy's 30-year plan targets 381 manned ships at roughly $40 billion a year — more than $1 trillion across 30 years, which the Congressional Budget Office put at 46% above the preceding five-year average appropriation [5][7]. Munitions replenishment, missile defense, and a commercial-launch boom (FAA-licensed launches and reentries rose from 14 in fiscal 2015 to 148 in fiscal 2024) push the same way [5]. But the revised children make clear this is not one uniform lift: the Army's fiscal 2026 request for Weapons and Tracked Combat Vehicles came in at $2.887 billion, below the $3.689 billion continuing-resolution baseline before it, the M10 Booker was cancelled after more than $1 billion spent, and the Navy cancelled the Constellation-class frigate in late 2025 [7][8]. Shipbuilding, munitions, missiles and space are up; heavy ground-armor procurement is flat-to-down, with value migrating toward upgrades, protection systems, and lighter or uncrewed vehicles.

Two forces cut across all three engines. Electrification remains a shared product transition on different clocks — EVs in cars, e-bikes and neighborhood golf carts in powersports, electric trucks and battery-tray demand in parts and bodies, even electric boats — but it decelerated. U.S. EV share was 9.4% of 2025 sales, down from 9.8% in 2024; hybrids hit a record 16% of sales in the second quarter of 2026 against battery-EVs at 6%; and battery-EVs remain about 2% of the registered fleet [4]. Hybrids are the swing fact for the whole subsector, because they preserve engine, transmission and exhaust content while adding electrical and power-electronics content — a bridge, not a cliff. And replacement demand puts a recurring floor under every child, because the installed base of vehicles, aircraft, ships, and railcars all eventually wears out — the North American freight-car fleet alone runs about 1.63 million cars at an average age of 20.4 years [6].

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7. Regulation

Transportation equipment is among the most heavily regulated corners of U.S. manufacturing, and the regime differs by child — but four regulatory forces recur:

• Vehicle safety. The National Highway Traffic Safety Administration (NHTSA) writes the Federal Motor Vehicle Safety Standards (FMVSS) that govern cars, trucks, trailers, bodies, RVs, and even low-speed golf carts (FMVSS No. 500) — and create demand for the safety-content children in parts. FMVSS No. 127 requires automatic emergency braking on essentially all new light vehicles with compliance by September 1, 2029; it is under administrative review with appeals held in abeyance, but the deadline currently stands [4]. Aircraft answer to the Federal Aviation Administration (FAA), which certifies every airframe, engine, and replacement part — and can gate revenue directly, as when it capped 737 MAX output at 38 a month, then raised it to 42 in October 2025 and 47 in 2026 [5]. Ships answer to the U.S. Coast Guard, rail to the Federal Railroad Administration (FRA), and off-highway vehicles and e-bike batteries to the Consumer Product Safety Commission, which approved publication of a proposed mandatory lithium-battery standard for micromobility products in June 2026 [8].

• Emissions and electrification — the mandate side was withdrawn. In February 2026 the Environmental Protection Agency finalized the rescission of the greenhouse-gas endangerment finding and repealed federal GHG standards for highway vehicles of every size, while leaving traditional air-pollutant rules in force [2][4][13]. That distinction matters at this level: the rules that create catalytic-converter demand are the pollutant rules, not the climate rules. Alongside it, NHTSA proposed in December 2025 rolling Corporate Average Fuel Economy standards back to roughly 34.5 mpg by model year 2031 from a trajectory near 50 mpg (not finalized as of mid-2026), and Congress revoked California's Clean Air Act waivers in June 2025 [2][4]. On the truck side the EPA's 2027 NOx rule keeps its start date and limit, though proposed amendments published July 14, 2026 remain unfinished [2]. The children disagree on one point worth flagging rather than resolving: 3361 and 3363 treat the June 2025 waiver revocation as having killed California's Advanced Clean Trucks rule, while 3362 reports ACT as a live supply pinch that has caused some suppliers to pause conventional motorhome-chassis sales in California and the states following its rules [2][3][4]. We state both and reconcile neither. The net for owners is that regulatory whiplash is itself a risk — the rules moved in both directions inside a single year (§9).

• Trade — now the most active force in the subsector. Three separate Section 232 regimes of 25% now apply: imported vehicles (from April 3, 2025) and many parts (May 3, 2025), plus a distinct 25% tariff on covered imported medium- and heavy-duty trucks and parts with an offset tied to U.S. assembly [2][11]. Steel and aluminum tariffs rose from 25% to 50% in June 2025 and were extended in September 2025 to softwood lumber and the imported lauan plywood the RV industry relies on [3][4]. Downstream, Commerce issued preliminary affirmative antidumping determinations on van-type trailers on July 30, 2026 — all-others rates of 4.29% for Canada and 7.10% for Mexico, and a preliminary 130.76% for China with countervailing rates including 82.37% for specified CIMC entities [3]. Import-dependent categories (bicycles, golf carts, snowmobiles) face their own Section 301 and antidumping duties [8]. On the water, USTR's Section 301 port-entry fees on China-built and China-linked ships phased in from October 14, 2025 and were suspended for one year on November 10, 2025 [7]. And the framework underneath all of it is unresolved: USMCA was not extended in its current form at the July 2026 review [4][12].

• Defense and domestic-content gates. The Jones Act (U.S.-built ships for domestic sea trade), International Traffic in Arms Regulations (ITAR) and the Committee on Foreign Investment in the United States (CFIUS) on defense assets, "Buy America" rules on transit railcars (generally more than 70% U.S. component cost plus U.S. final assembly) and NDAA Section 7613 barring Chinese state-owned transit builders, and the FRA's December 2024 freight-car rule restricting components from countries of concern all govern who may compete on the government side — compliance as a moat, not just a cost [6][7]. The newest entrant in this family points at the commercial side: Commerce's connected-vehicle rule restricts covered vehicle software linked to China or Russia from model year 2027 and covered connectivity hardware from model year 2030 [4].

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8. Consolidation — and why the subsector looks deceptively un-concentrated

At the subsector level the federal data reads as un-concentrated — the top four firms hold barely one dollar in four:

Why the subsector looks less concentrated than almost every child — the counter-intuitive part, and the central structural fact of this level. The subsector HHI of 251.6 (well below the ~1,500 line the U.S. Department of Justice treats as "moderately concentrated") sits below every child except parts. That is not because the market is genuinely competitive at the top; it is because the seven children have almost entirely non-overlapping leaders. The firms that dominate cars (GM, Ford, Toyota) are not the ones that dominate aerospace (Boeing, RTX), which are not the ones that dominate railcars (Greenbrier, Trinity), warships (General Dynamics, HII), or motorcycles (Harley). Pooling seven separate oligopolies whose champions never compete dilutes any one firm's share toward zero.

The revised children show that this dilution is fractal — it happens at every level, not just here. Motor vehicles reads CR4 53.3% against the car child's 58.3% and the truck child's 76%, because the four biggest carmakers and the four biggest truck makers are eight different companies [2]. Parts reads HHI 102.2, below every one of its eight children [4]. Bodies/trailers reads HHI 494, an average of genuinely fragmented commercial sub-industries (bodies ~238, trailers ~381) and recreational oligopolies (motorhomes ~2,023 with CR4 ~82.5%) [3]. Aerospace reads a "moderate" 1,182.7 while four firms make 96.7% of complete missiles and space vehicles and 98.4% of their propulsion [5]. 3369 calls its own 655.8 a "statistical mirage," lower than any of its three children [8]. Rail reads 1,017 while the FRA counts six actual freight-car builders and Trinity plus Greenbrier build roughly 80% of new North American cars [6]. Ship/boat's blended CR4 of 45.7% sits between ship building's 68.5% and boat building's 26.7% [7].

The honest reading: NAICS 336 is not one market but seven adjacent oligopolies, each of which is in turn several. The blended number understates concentration at every rung. Use the deepest available child-level figure, never the 251.6, to judge any single business.

The active consolidation stories also differ by child, but four logics now recur across the subsector. Private-equity roll-ups of fragmented, cash-generative tails: Apollo/Tenneco and KKR/Marelli in parts, the truck-body roll-up (Shyft into Aebi Schmidt, closed July 1, 2025), Apollo's $3.6 billion purchase of Barnes Group and Warburg Pincus/Berkshire Partners' ~$3 billion purchase of Triumph in aerospace, and Wells Fargo Rail into GATX and Brookfield (closed January 2026, lifting GATX's share of the lessor-owned fleet from ~13% to ~25%) [3][4][5][6]. Scale mega-mergers to fund expensive transitions or buy adjacency: American Axle plus Dowlais completed in February 2026 to form Dauch (~$12 billion of combined revenue), Allison's ~$2.7 billion purchase of Dana's off-highway business, Terex plus REV Group (February 2, 2026), MasterCraft plus Marine Products (May 2026), and Boeing's vertical reabsorption of Spirit AeroSystems (December 8, 2025) [3][4][5][7]. Spin-offs to sharpen focus, now all complete: PHINIA out of BorgWarner, AUMOVIO out of Continental (September 2025), Versigent out of Aptiv (April 1, 2026), Indian Motorcycle out of Polaris (February 2026) [4][8].

The fourth logic is new and runs the other way: on parts of the defense side, the government is deliberately de-concentrating the base it spent the 1990s consolidating. The Pentagon is funding new entrants at chokepoints, most visibly backing L3Harris's solid-rocket-motor carve-out with roughly $1 billion ahead of a 2026 IPO while L3Harris separately sells 60% of Aerojet's space-propulsion business to AE Industrial for $845 million; and Northrop has petitioned to lift the 2018 Federal Trade Commission firewall order governing its solid-rocket-motor sales, with Lockheed Martin publicly opposed [5]. Whether the two-supplier structure tightens or loosens is a live question, not a settled one. The through-line across all four logics: separate the declining internal-combustion and legacy-hardware assets from the growth-electrification, electronics, and capacity-constrained defense assets, and put each in the hands best suited to own it.

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9. Risks

The subsector inherits the union of its children's risks; their weight varies by child, but they rhyme:

• Deep cyclicality amplified by high fixed costs — universal, though driven by three different cycles (consumer, freight, defense budget), which is also the diversifier. The children now supply the amplitude: real sectoral output in metal stamping fell 20.2% in 2008, 29.7% in 2009, rebounded 43.7% in 2010, then fell 14.7% in 2020; railcar orders fell two-thirds between 2022 and 2025; Polaris's sales fell 20% and its net income from $503 million to $111 million in a single year [4][6][8].

• Trade and tariff exposure, now quantified — the 2025 Section 232 regime added an estimated ~$30 billion of cost across the auto industry alone; GM booked $3.1 billion, BorgWarner $108 million on ~$918 million of imports (68% of it Mexican-origin), Gentex about 110 basis points of gross margin, Harley-Davidson roughly $67 million, and BRP suspended fiscal-2027 guidance outright [2][4][8][11]. Steel and aluminum at 50% touch every child. The unresolved USMCA review compounds all of it [12].

• An electrification transition that can be mistimed in either direction — this is a sharpening of the old "money-losing transition" risk. Building too late strands you; building too early destroys capital just as fast. GM took $7.6 billion of EV-related charges in 2025 and Ford's Model e segment ran at −72.1%, but ZF also lost €2.1 billion on an e-mobility impairment tied to projects whose slower-than-expected adoption would not support expected profitability, LiveWire's electric-motorcycle segment lost $73.8 million, and BRP booked roughly CA$233 million of EV and light-mobility impairment [2][4][8]. In an industry with multi-year tooling cycles, both errors are expensive.

• Regulatory reversals and whiplash — the same 2025–26 rule changes that help one child or one year can hurt the next; both directions moved in a single year, and repeated reversals shorten planning visibility for tooling that outlives an administration [4].

• Foreign competition and foreign ownership — cost-advantaged Chinese makers pressure cars, bikes, and golf carts (import-based upstarts pushed domestic cart makers to roughly a third of the U.S. market); large blocks of parts, trucks, transit railcars, and mid-tier shipyards are foreign-owned [4][6][8].

• Customer concentration — and one correction the children force. On the defense side it is extreme (one buyer), and in parts it is now measured: Dana's ten largest customers were 76% of 2025 sales, BorgWarner's 71%, and GM alone was 34% of Nexteer's revenue [4]. But the parent's old claim that the freight side means "a few large fleets" needs qualifying: the trucking customer base is not concentrated at all — roughly 580,000 active U.S. motor carriers, 91.5% of them running ten or fewer trucks — what concentrates is order flow, in the large fleets whose block orders swing a quarter [2]. Rail shows a different shape again: FreightCar America sold 78% of its 2025 output to financial institutions rather than railroads [6].

• Program cancellation, not just budget cyclicality — a risk the parent previously lacked. On the government side the customer can simply stop: the Navy cancelled the Constellation-class frigate in late 2025, and the Army ceased M10 Booker procurement after more than $1 billion spent and 26 vehicles delivered against a contract contemplating up to 96 [7][8]. Fixed-price development overruns land on the manufacturer, and the Sentinel ICBM's 81% cost breach to roughly $141 billion is the scale of that tail [5].

• Execution, supply-chain single points, and skilled-labor scarcity — output is gated by the slowest input and by trades that take years to train; margins can stay negative through a production ramp even with a full backlog. In a GAO survey, 15 of 17 aviation manufacturers reported difficulty hiring enough skilled workers and 15 reported difficulty obtaining materials; a single domestic producer supplies the ammonium perchlorate base for solid rocket propellant; the GAO estimates the shipbuilding industrial base needs 174,000 new workers over a decade; and a single aluminium-supplier fire cost Ford about $2 billion in 2025 [2][5][7][15]. The children also flag a shared labor pool — ship and boat yards draw on the same welders, pipefitters, and electricians — without settling whether the 2024–25 decline in boat-building payrolls is a transfer or a separate shortage [7].

• Physical risk to workers is above the manufacturing norm, and unevenly. The Bureau of Labor Statistics put the 2024 recordable injury and illness rate for transportation-equipment manufacturing as a whole at 3.2 cases per 100 full-time workers — but at 5.1 in bodies and trailers, the most labor-intensive child [3][14]. Read it as a proxy for how much of a child's cost is hands rather than robots.

• Leverage, disclosure quality, and litigation tails in the private/PE-owned and safety-critical corners — the First Brands aftermarket collapse (Chapter 11 in September 2025 with more than $10 billion of liabilities, followed by fraud charges against its executives in 2026) is the standing warning on capital structure; a $462 million Missouri underride verdict against Wabash, later reduced, is the warning on product liability [3][4].

The one genuinely diversifying feature is structural, and 2025 is the proof: cars rose 2.4% while heavy-truck retail fell ~13%, and a supply-constrained Navy backlog ran beside a boat market in its third year of destocking [2][7]. Because the three demand engines answer to different masters, a bad consumer year, a bad freight year, and a defense downturn rarely coincide — so a position spanning NAICS 336 is less correlated than the label suggests.

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10. How to invest & outlook

How to invest. There is no single-ticker or single-ETF way to own NAICS 336; you build it from the children, and the practical move is to decide which of the three engines you want, then pick the child and ownership route that gives the cleanest exposure. All tickers below merely locate the securities; this is not investment advice, and prices, yields, and multiples should be checked live.

• A consumer/rate-cycle bet → cars (GM, Ford, Tesla, foreign makers via ADRs; EV funds DRIV, KARS, IDRV), RVs (Thor, Winnebago), boats (a diversified builder plus the remaining pure-plays — note Marine Products is no longer standalone), powersports (Polaris, BRP), or motorcycles (Harley-Davidson) — plus the aftermarket-and-fleet tilt (parts distributors, the record-old ~289-million-vehicle fleet) for lower cyclicality [4][7].

• A freight/industrial bet → heavy trucks (PACCAR, engine-maker Cummins), freight trailers (Wabash, the only listed pure-play and itself only ~65% new trailers by revenue), or railcars and rail (Greenbrier, Trinity, Wabtec, lessor GATX) [3][6].

• A defense/aerospace bet → the large-cap anchors (Boeing, GE Aerospace, RTX, Lockheed, General Dynamics, HII), the aftermarket-quality compounders (TransDigm, HEICO, Howmet), the higher-risk listed new-space and missile-parts cohort (Rocket Lab, Karman, and the expected L3Harris motor spin-off), or diversified A&D ETFs (ITA, PPA, XAR) — the lower-volatility way to own the whole defense-and-aerospace spine at once [5].

• Diversified basket → a multi-child Tier-1 (BorgWarner, Magna, Aptiv, Dana, Dauch) buys several parts industries in one holding; General Dynamics buys warships and armor. If you hold an old note that says AXL, it is now DCH [4].

• Private → rarely the assembler itself; reach the subsector through suppliers, aftermarket and remanufacturing roll-ups, dealer and leasing/rental fleets, floor-plan private credit, and venture stakes in EV/battery/charging, electric-air-taxi (eVTOL), and commercial-rocket ventures. This route is widening, not narrowing, as diversified public parents exit the consumer-vehicle children [8].

Because these are cyclicals (defense excepted), judge valuation across a full cycle — through-cycle margins, backlog trend, fleet utilization, net asset value of owned lease fleets — rather than on one peak or trough year, and note that capital return skews toward buybacks over rich dividends outside the defense names. Select on defensibility, not on category: the 29-point margin gap between Allison and Dana inside a single child says more about where to put money than any subsector average does [4].

Outlook (forward-looking judgment, not a forecast of record). The three engines are on offset clocks, which is the whole investment case:

• The consumer complex (autos, RVs, boats, powersports — the ~72% that sets the subsector's tempo) is mature and choppy: a cost tailwind from looser fuel-economy and emissions rules, offset by higher tariffs, lost EV subsidies, money-losing EV programs, and a rate-sensitive, destocking recreational side where RVIA forecasts roughly 314,000 RV units in 2026 (about −8%) and boat units fell 8.8% in 2025 [3][7]. Net: soft and cyclical into 2026 — and no longer a single story, since motorhomes and towables moved in opposite directions through May 2026.

• The freight layer (heavy trucks, trailers, railcars) is climbing out of one of its deepest downcycles — ACT projects ~171,000 Class 8 units in 2026, down ~18%, even as December 2025 order boards hit a three-year high on EPA-2027 pre-buying, and trailer builds hit their lowest level since 2010 against a 21%-lighter backlog [2][3]. Expect soft deliveries into 2026, a possible pre-buy bump around 2027, then an air-pocket.

• The aerospace-and-defense spine is the standout: an unusually synchronized upcycle — a record commercial-jet backlog (the children's sources put it above 17,000 aircraft on one count and 16,133 on another, both more than a decade of work at current build rates; we carry both rather than pick), a multi-year MRO wave, robust defense budgets, munitions replenishment, a Navy shipbuilding backlog the service cannot fully fund out of, and a commercial-launch boom [5][7]. Here the swing factor is supply, not demand — whether build rates, the supplier base, and solid-rocket-motor and propellant capacity can keep pace. Boeing's return to a full-year net profit in 2025, its first since 2018, while its commercial unit still lost money at a −17.1% operating margin, captures the moment: the order book is the envy of manufacturing, and converting it into margin and cash is the unfinished job [5].

Two figures the children genuinely disagree on, and we do not average. U.S. light-vehicle sales for 2025 read as 16.2 million on NADA's count carried by the motor-vehicle and parts children, but roughly 15.3 million in one parts sub-industry's sourcing [2][4]; and 2025 air-travel volume reads as ~5.2 billion travelers on IATA's basis against more than 10 billion passengers on another industry tracker's — different bases, same direction [5]. Neither dispute changes the shape of the outlook, but either would change a model built on the exact number.

Through all of it the structural story holds: seven stable oligopolies whose aftermarket, finance, and leasing annuities cushion a brutal new-build cycle — and whose three demand engines rarely fail at once. Because the money is ~72% automotive, the subsector's headline fortunes will track the consumer-vehicle story first; but its quality and its diversification come from the aerospace, defense, and freight halves that march to entirely different drums.

For the full detail on any of the seven — scope, company rosters, unit economics, and sourcing — read the child primer. This page is the bridge across them.

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Sources

Synthesized from the seven child primers (NAICS 3361, 3362, 3363, 3364, 3365, 3366, 3369) and our ground-truth federal statistics for NAICS 336. Where a figure is this level's own, it is drawn from the subsector ground-truth file [1]; child-specific figures carry the child's citation.

1. Histometrics ground-truth federal statistics, NAICS 336 (subsector): U.S. Census Bureau, 2022 Economic Census — Concentration statistics (receipts $1,023.73B; 9,473 firms; CR4 24.1%, CR8 38.2%, CR20 57.1%, CR50 69.9%; HHI 251.6) and County Business Patterns 2023 (11,691 establishments; 1,682,910 employees; $139.10B annual payroll; $36.73B first-quarter payroll). https://www.census.gov/programs-surveys/economic-census.html

2. Histometrics primer — NAICS 3361 Motor Vehicle Manufacturing (receipts $390.2B; 277,328 jobs; 331 establishments; $30.9B payroll, ~$111,000 average pay; CR4 53.3%, CR8 79.5%, CR20 97.6%, HHI ~1,018; cars ~92% of receipts vs. heavy trucks ~8%; 2025 light-vehicle sales 16.2M, +2.4%, vs. heavy-truck retail −13%; ACT ~171,000 Class 8 units in 2026; ~580,000 motor carriers, 91.5% with ≤10 trucks; GM material cost ~2/3 of automotive cost of sales and $3.1B tariff cost; PACCAR bought-in content ~85%, PACCAR Parts $6.67B; EPA February 2026 GHG rescission; Section 232 tariffs on vehicles, parts and medium/heavy trucks; $7,500 EV credit ended September 30, 2025; Novelis fire ~$2B).

3. Histometrics primer — NAICS 3362 Motor Vehicle Body and Trailer Manufacturing (receipts $72.3B; 170,535 jobs; 2,199 establishments; $10.07B payroll, ~$59,000 average pay; 1,880 firms; CR4 37.1%, HHI 494, with sub-industry HHIs from ~238 to ~2,023; commercial ~52% of receipts / ~61% of jobs; 2026 RV shipments −14.4% through May, towables −17.2%, motorhomes +11.8%; RVIA 2026 forecast ~314,000 units; 2025 trailer output 200,485 vs. 245,344; backlog −21%; Wabash trailer gross margin 12.4%→1.9% and Parts & Services 18.6%; July 30, 2026 preliminary antidumping determinations on van-type trailers; Section 232 steel/aluminum to 50% and lumber/lauan extension; Terex–REV Group and Shyft–Aebi Schmidt mergers; ~86% of North American RV output in Indiana; BLS injury rate 5.1).

4. Histometrics primer — NAICS 3363 Motor Vehicle Parts Manufacturing (receipts $278.2B; 587,237 jobs; 4,659 establishments; $36.3B payroll, ~$62,000 average pay; 3,814 firms; CR4 14.3%, CR8 22.4%, CR20 37.2%, HHI 102.2; eight component industries; ~289M-vehicle installed fleet at 12.8-year average age; U.S. EV share 9.4% in 2025 vs. 9.8% in 2024, hybrids 16% in Q2 2026, BEVs 2% of the registered fleet; North American production 15.29M units in 2025; Allison 37.5% vs. Dana 8.1%; customer concentration at Dana 76%, BorgWarner 71%, Nexteer/GM 34%; ~$30B industry tariff cost, BorgWarner $108M, Gentex ~110 bps; USMCA not extended at the July 2026 review; EPA February 2026 rescission; FMVSS 127; connected-vehicle rule; American Axle→Dauch, Aptiv→Versigent, Continental→AUMOVIO; ZF €2.1B loss; First Brands).

5. Histometrics primer — NAICS 3364 Aerospace Product and Parts Manufacturing (receipts $203.5B; 428,728 jobs; 1,907 establishments; $46.3B payroll, ~$108,000 average pay; 1,379 firms; CR4 63.4%, CR8 76.9%, CR20 86.0%, HHI 1,182.7; commercial cluster ~82% / ~$166.8B and missile-space ~18% / ~$36.7B; four firms at 96.7% of complete missiles and 98.4% of propulsion, with most detail HHIs suppressed; aircraft/spacecraft exports ~$134B in 2024 and A&D surplus ~$109B in 2025; full A&D value chain ~$850B; Census space economy $142.5B of GDP in 2023; Boeing $567B commercial backlog, −17.1% commercial margin, Spirit reacquisition December 8, 2025; GE Aerospace services $25.0B of $33.3B at 26.6%; FAA 737 MAX rate 38→42→47; defense topline ~$839B for FY2026; FAA launches 14 (FY2015) → 148 (FY2024); jet backlog 17,000+ vs. 16,133 and traffic ~5.2B vs. >10B on differing bases; Sentinel 81% cost breach; L3Harris motor carve-out and AE Industrial/Aerojet).

6. Histometrics primer — NAICS 3365 Railroad Rolling Stock Manufacturing (receipts ~$12.0B; 27,831 jobs; 220 establishments; $2.46B payroll, ~$88,000 average pay; 140 firms; CR4 54.9%, CR8 72.5%, CR20 89%, HHI 1,017; FRA counts six new-freight-car manufacturers; Trinity plus Greenbrier ~80% of new North American cars; orders 60,734 in 2022 → 20,361 in 2025, deliveries 31,205, backlog 34,273 → 23,431; fleet ~1.63M cars at 20.4 years; Greenbrier Manufacturing $2.99B at 14.5%, Trinity Rail Products 5.2% at ~50% utilization, Wabtec Freight $8.04B at 19.5% with 58% aftermarket; FreightCar America 78% of sales to financial institutions; GATX/Brookfield–Wells Fargo Rail closed January 2026; leasing booked under NAICS 532411; IIJA $300M a year for rail-vehicle replacement).

7. Histometrics primer — NAICS 3366 Ship and Boat Building (receipts $46.95B; 150,621 jobs; 1,427 establishments; $10.32B payroll; 1,278 firms; CR4 45.7%, CR8 53.5%, CR20 66.9%, level HHI suppressed, with ship CR4 68.5% vs. boat CR4 26.7% and boat HHI 278.8; ships ~64% of receipts from ~35% of plants; GD Marine Systems ~$16.7B at 7.0%, HII ~$9.6B with Newport News 5.1% / Ingalls 7.6% and $350M unfavorable catch-up adjustments; Brunswick Boat segment 2.1% vs. 4.1%; 2025 powerboat units −8.8% to 215,237; ~37,000 public-naval-yard workers excluded, true total ~185,000; Navy plan 381 ships at ~$40B/yr, >$1T over 30 years, 46% above the prior five-year average; 18 of 49 attack submarines undeployable; Constellation cancellation and LSM split; USTR port fees imposed then suspended; Jones Act, EO 14269 and the SHIPS for America Act; MasterCraft–Marine Products).

8. Histometrics primer — NAICS 3369 Other Transportation Equipment Manufacturing (receipts ~$20.45B; 40,630 jobs; 948 establishments; $2.71B payroll; 852 firms against 855 summed across three children; CR4 42.5%, CR8 66.7%, CR20 83.1%, HHI 655.8, below every child — 336991 CR4 65.3%, 336992 CR4 85.1% and HHI 2,289, 336999 CR4 61.9% and HHI 1,229; child pay ~$53,000 / ~$67,700 / ~$74,800; ~97–99% of bicycles and ~99% of 2024 golf-cart imports from China; GD Combat Systems $9.246B with $27.2B backlog and $8.131B fixed-price; Harley 124,500 shipments −16%, motorcycle gross margin 28.0%→24.2%, $29M segment operating loss against $339M consolidated net income, ~$67M tariff cost; Polaris Off-Road $5.71B and 2024 sales $8.93B→$7.18B; snowmobile retail 125,000→90,000; Army FY2026 tracked-vehicle request $2.887B vs. $3.689B baseline; M10 Booker cancellation; LiveWire $73.8M loss; BRP CA$233M impairment and suspended FY27 guidance; Indian separation and Textron's Industrial-segment announcement).

9. Aerospace Industries Association, 2025 Facts & Figures / Industry Impact (aircraft and spacecraft exports ~$134B in 2024; A&D trade surplus ~$109B in 2025; full A&D value chain ~$850B). https://www.aia-aerospace.org/industry-impact/

10. Alliance for Automotive Innovation, Driving the U.S. Economy and Innovation (auto sector ~3–3.5% of GDP; ~11 million jobs supported; 20 automakers operating 55 light-vehicle assembly plants in 15 states). https://www.autosinnovate.org/initiatives/the-industry

11. Congressional Research Service / U.S. Customs and Border Protection, Section 232 Tariffs on Automobiles and Automobile Parts (25% on imported vehicles from April 3, 2025 and many parts from May 3, 2025; partial USMCA content relief). https://www.congress.gov/crs-product/IN12545

12. Holland & Knight, Industry Stakeholders Discuss State of USMCA at USTR Hearing (July 2026 review; the administration declined to extend USMCA in its current form). https://www.hklaw.com/en/insights/publications/2025/12/industry-stakeholders-discuss-state-of-usmca-at-ustr-hearing

13. U.S. Environmental Protection Agency, Final Rule: Rescission of Greenhouse Gas Endangerment Finding and Emission Standards for Motor Vehicles (February 2026; traditional air-pollutant requirements remain in force). https://www.epa.gov/regulations-emissions-vehicles-and-engines/final-rule-rescission-greenhouse-gas-endangerment

14. U.S. Bureau of Labor Statistics, Table 1. Incidence rates of nonfatal occupational injuries and illnesses by industry, 2024 (transportation equipment manufacturing 3.2 and NAICS 3362 5.1 cases per 100 full-time workers). https://www.bls.gov/web/osh/table-1-industry-rates-national.htm

15. U.S. Government Accountability Office, Navy Shipbuilding: Challenges Impacting Shipbuilders' Ability to Meet the Navy's Goals, GAO-25-106286 (seven builders of Navy battle-force ships; 174,000 additional workers needed over a decade). https://files.gao.gov/reports/GAO-25-106286/index.html