Report Highlights

U.S. Automotive Engine Market: Market Overview

The U.S. automotive engine market is one of the most heavily policy-conditioned manufacturing sectors in the country, shaped by decades of federal emissions standards, fuel economy mandates, and trade policy. In 2024, the market is valued at USD 28.6 billion, with production concentrated in the Midwest — Ohio, Michigan, and Indiana account for more than 60% of domestic engine manufacturing output. The market structure reflects a dual dynamic: legacy internal combustion engine platforms that still dominate OEM procurement, and a fast-expanding hybrid and alternative fuel powertrain segment responding directly to regulatory pressure from the Environmental Protection Agency and NHTSA.

Government has been the dominant structural force in this market since the Clean Air Act Amendments of 1990, with private sector innovation largely reactive to compliance requirements rather than purely market-led. Ford, GM, and Stellantis continue to invest in engine platform upgrades primarily because CAFE and GHG standards compel redesign cycles. However, independent Tier-1 suppliers such as BorgWarner and Cummins are now driving technology-side leadership, particularly in turbocharging, electrified boosting, and natural gas engine systems, areas where regulatory incentives have created genuine first-mover commercial advantage independent of OEM direction.

Policy-Driven Growth in Automotive Engines

Three specific policy mechanisms are directly translating into engine market growth. First, the EPA's Light-Duty Vehicle Greenhouse Gas Emissions Standards for Model Years 2027–2032, published in the Federal Register in March 2024, mandate fleet average CO2 reductions to 85 grams per mile by 2032. This requires OEMs to deploy high-efficiency hybrid combustion systems at scale, driving an estimated USD 4.2 billion in engine retooling investment across the Ford Lima Engine Plant, GM's Romulus Powertrain facility, and Stellantis' Trenton South engine complex. Compliance is not optional — non-conforming fleets face civil penalties under 42 U.S.C. § 7524 of up to USD 44,539 per violation per vehicle.

Second, the Inflation Reduction Act of 2022 (IRA, Public Law 117-169) created the Advanced Manufacturing Production Credit under Section 45X, providing USD 35 per kilowatt-hour for qualifying clean vehicle components manufactured domestically. Engine systems integrated into qualified hybrid vehicles are eligible, incentivising OEMs to onshore previously offshored engine subassembly lines. Third, the Department of Energy's Vehicle Technologies Office awarded USD 175 million under the FY2023 Funding Opportunity Announcement DE-FOA-0002892 for advanced combustion engine research, specifically targeting opposed-piston and lean-burn architectures. Each DOE grant award directly funds supplier R&D pipelines and accelerates commercial readiness timelines for next-generation powertrains.

Regulatory Barriers and Compliance Costs

The most significant regulatory barrier to market entry is the EPA's Certificate of Conformity requirement under 40 CFR Part 86, administered by the EPA's Office of Transportation and Air Quality (OTAQ). Every engine family sold in the U.S. market must obtain a Certificate of Conformity before sale or importation, a process requiring full emissions testing at EPA-recognized laboratories and submission of comprehensive technical data packages. For a new engine family, certification timelines typically run 12 to 18 months from initial application to certificate issuance, with testing costs ranging from USD 800,000 to USD 2.5 million per engine family. This creates a formidable cost barrier for foreign entrants and smaller domestic Tier-2 manufacturers attempting to introduce novel combustion architectures.

A second significant barrier is California Air Resources Board (CARB) certification under Title 13 of the California Code of Regulations, Section 1961.4, which applies to engines sold in the 17 states that have adopted California's emissions standards under Clean Air Act Section 177. CARB standards are materially stricter than federal EPA thresholds, requiring separate certification at the California Air Resources Board's Haagen-Smit Laboratory. The dual-certification requirement effectively doubles testing costs and extends market entry timelines, with some engine families requiring up to 30 months to achieve both EPA and CARB approval simultaneously. Manufacturers who fail to maintain CARB certification risk losing access to markets representing approximately 35% of total U.S. new vehicle registrations.

Policy-Created Opportunities in the U.S. Engine Market

The IRA's Section 45X Advanced Manufacturing Production Credit creates a direct commercial opportunity for domestic engine component manufacturers. Suppliers producing turbochargers, fuel injection systems, and hybrid drive components for qualifying vehicles can claim production credits that reduce effective manufacturing cost by an estimated 8–12% per unit. BorgWarner's Ithaca, New York turbocharger facility and Delphi Technologies' fuel systems operations in Michigan are already positioned to benefit, with both companies having filed IRA credit eligibility assessments with the IRS in fiscal year 2024. This credit structure will remain active through at least 2032, providing a durable competitive advantage for domestically manufactured engine sub-systems over imported equivalents.

The Department of Transportation's National Electric Vehicle Infrastructure (NEVI) Formula Program, funded at USD 5 billion under the Infrastructure Investment and Jobs Act (Public Law 117-58), is creating an indirect but significant opportunity for hybrid engine demand. As charging infrastructure deployment proceeds along designated Alternative Fuel Corridors, plug-in hybrid electric vehicle (PHEV) adoption is accelerating in range-anxiety-sensitive segments including commercial fleets and rural light trucks. PHEV powertrains require fully certified combustion engines, and EPA's Clean Trucks Plan — which sets NOx emission standards for heavy-duty vehicles under 40 CFR Part 1036 effective model year 2027 — is expanding the addressable engine market to include medium-duty hybrid commercial platforms currently underpenetrated by domestic suppliers.

Market at a Glance

Leading Market Participants

• General Motors
• Ford Motor Company
• Stellantis
• Cummins Inc.
• BorgWarner
• Delphi Technologies
• Honda Manufacturing of America
• Toyota Motor Manufacturing
• Freightliner (Daimler Truck North America)
• PACCAR Inc.

Regulatory and Policy Environment

The primary legislation governing the U.S. automotive engine market is the Clean Air Act (42 U.S.C. § 7401 et seq.), with the EPA's Office of Transportation and Air Quality as the principal regulatory authority. The most consequential current rulemaking is the EPA's Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles (89 FR 27842), finalised in March 2024, which establishes the most stringent fleet-average CO2 and criteria pollutant limits in U.S. history. Manufacturers must submit compliance plans to EPA by model year 2026 production launch, with annual averaging, banking, and trading (ABT) provisions under 40 CFR Part 86 Subpart S providing limited flexibility. NHTSA separately administers CAFE standards under 49 U.S.C. § 32902, with the current final rule setting 49 mpg fleet average for passenger cars by model year 2031.

Compared to regional peers, the U.S. framework is structurally more complex than Canada's Canadian Environmental Protection Act (CEPA) regime, which largely mirrors EPA standards, and more technology-prescriptive than Mexico's NOM-044-SEMARNAT-2017, which tracks Euro VI rather than U.S.-specific test procedures. Upcoming regulatory changes include EPA's expected finalisation of Tier 4 evaporative emissions standards for small engines by Q2 2026 and NHTSA's anticipated mid-term review of MY2029–2031 CAFE targets scheduled for Q4 2026, both of which will require OEM product planning adjustments. The CARB Advanced Clean Cars II regulation, which mandates 100% zero-emission vehicle sales in California by 2035, creates an effective 10-year window for hybrid engine platforms before the state-level combustion engine phase-out takes force.

Long-Term Policy Outlook for the U.S. Engine Market

By 2032, the U.S. automotive engine market will be operating under the full compliance weight of EPA's MY2027–2032 GHG standards and NHTSA's CAFE final rule, with a clear regulatory trajectory toward near-zero tailpipe emissions by the mid-2030s. The most probable policy development is an EPA rulemaking for MY2033–2035 standards, expected to be proposed by 2028, which will push remaining ICE-only platforms out of passenger car segments entirely. However, light trucks and commercial vehicles — which account for more than 70% of U.S. new vehicle sales — will retain hybrid powertrain eligibility through the forecast period, sustaining engine market revenue even as pure ICE volume contracts. The DOE's continued funding of combustion efficiency research under the Vehicle Technologies Office annual appropriation, which averaged USD 340 million per year from 2021 to 2024, will maintain U.S. supplier competitiveness in precision combustion and alternative fuel engine architectures.

The long-term regulatory outlook also includes increasing integration of engine policy with energy security priorities. The DOE's Sustainable Aviation Fuel and low-carbon fuel standard discussions at the federal level, combined with the IRA's alternative fuel vehicle refuelling property credit under Section 30C, signal that natural gas and hydrogen combustion engines will receive dedicated regulatory support beyond 2028. Cummins' hydrogen internal combustion engine development programme and PACCAR's natural gas powertrain roadmap for Kenworth and Peterbilt trucks are directly aligned with this trajectory. The phased tightening of the EPA's Clean Trucks Plan NOx standards — 0.035 g/bhp-hr by 2031 under 40 CFR Part 1036 — will force a final technology transition in the heavy-duty segment that represents the engine market's most durable long-term revenue base.