What is the U.S. tariff rate on internal combustion engines?

USITC calculated duties imply an effective rate of 6.91% in Jun 2026 (calculated duties ÷ covered customs value, USITC DataWeb). The parseable Column 1 General line-rate range is 0%–2.5%; individual lines are called “Free” only when the official General field is literally Free, and product, origin, preference and tariff mix can contribute to the observed-rate difference.

What are the statutory MFN line rates for internal combustion engines?

The parseable Column 1 General line-rate range is 0%–2.5% across the family's 37 eight-digit HTS lines in the 2026 Harmonized Tariff Schedule (headings 8407, 8408, 8409). “Free” means the official General field is literally Free for a line; it does not determine final entry liability.

Which countries supply the most internal combustion engines to the U.S.?

Top retained sources in 2025: Mexico ($9.9B at 9.31%), Japan ($3.7B at 13.7%), Canada ($3.4B at 2.71%). Mexico holds 35.9% of total family import customs value. Retained sources cover 90.9%; their HHI is 1780, a lower bound whose floor falls in the moderately concentrated range without classifying the omitted tail.

How much internal combustion engines does the U.S. import?

$27.7B of customs value in 2025, with $3.5B in USITC Calculated Duties — an effective calculated-duty rate of 12.59%.

Is the U.S. a net importer of internal combustion engines?

Yes — a net importer in 2025: $27.7B imported vs $8.8B exported (exports are 32% of imports).

Tariff monitor · Machinery & Equipment

Internal Combustion Engines: Statutory & Effective Tariff Rates

USITC Column 1 General rates for 37 internal combustion engines HTS lines (parseable range 0%–2.5%). Effective rate Jun 2026: 6.91%; monthly history since 2014.

The short answer

The observed effective calculated-duty rate on U.S. imports of internal combustion engines was 6.91% in Jun 2026, down from 10.36% a year earlier — USITC Calculated Duties divided by covered customs value. The Column 1 General line-rate range is 0%–2.5% across 37 HTS lines in the 2026 schedule; individual lines are called “Free” only when the official General field is literally Free, which still does not determine a shipment’s final duty. Mexico is the largest source, holding 35.9% of 2025 imports.

Statutory rates from the schedule

Gasoline and diesel piston engines and their parts — prime movers for gensets, pumps, compressors, and mobile equipment. This family covers HTS headings 8407, 8408, 8409: 37 eight-digit rate lines with a parseable Column 1 General range of 0%–2.5% in the 2026 schedule. “Free” means the official General field is literally Free for that line; it does not determine final entry liability.

Observed calculated-duty data

Latest month on record (2026-06): 6.91% effective on $2.5B of imports, versus 10.36% in the same month a year earlier. The monthly archive holds 150 observations from 2014-01 through 2026-06.
In 2025, U.S. imports for consumption in this family totaled $27.7B in customs value, with $3.5B in USITC reported calculated duty on $27.7B of covered customs value: an effective calculated-duty rate of 12.59%. The aggregate reflects the recorded entry mix but does not attribute the result to a specific legal provision.
A year earlier the effective calculated-duty rate was 2.29%, so the observed rate rose 10.3 points.
Top source countries in 2025: Mexico ($9.9B at 9.31%), Japan ($3.7B at 13.7%), Canada ($3.4B at 2.71%), Germany ($2.1B at 14.32%), South Korea ($1.7B at 7.59%).
Reported freight and insurance equaled 2.08% of covered customs value in 2025 ($523.9M total); charge coverage was 90.9% of customs value, from USITC DataWeb. It is shown alongside the effective calculated-duty rate and is not part of the customs-value duty base.

Representative rate lines

8407.10.00: Aircraft engines · MFN Free
8407.21.00: Outboard motors · MFN Free
8407.29.00: Other · MFN Free
8407.31.00: Of a cylinder capacity not exceeding 50 cc · MFN Free
8407.32.10.00: To be installed in tractors suitable for agricultural use · MFN Free
8407.32.20: To be installed in vehicles of subheading 8701.21, 8701.22, 8701.23, 8701.24 or 8701.29, o · MFN Free
8407.32.90: Other · MFN Free
8407.33.10: To be installed in tractors suitable for agricultural use · MFN Free

Frequently asked questions

What is the U.S. tariff rate on internal combustion engines? USITC calculated duties imply an effective rate of 6.91% in Jun 2026 (calculated duties ÷ covered customs value, USITC DataWeb). The parseable Column 1 General line-rate range is 0%–2.5%; individual lines are called “Free” only when the official General field is literally Free, and product, origin, preference and tariff mix can contribute to the observed-rate difference.
What are the statutory MFN line rates for internal combustion engines? The parseable Column 1 General line-rate range is 0%–2.5% across the family's 37 eight-digit HTS lines in the 2026 Harmonized Tariff Schedule (headings 8407, 8408, 8409). “Free” means the official General field is literally Free for a line; it does not determine final entry liability.
Which countries supply the most internal combustion engines to the U.S.? Top retained sources in 2025: Mexico ($9.9B at 9.31%), Japan ($3.7B at 13.7%), Canada ($3.4B at 2.71%). Mexico holds 35.9% of total family import customs value. Retained sources cover 90.9%; their HHI is 1780, a lower bound whose floor falls in the moderately concentrated range without classifying the omitted tail.
How much internal combustion engines does the U.S. import? $27.7B of customs value in 2025, with $3.5B in USITC Calculated Duties — an effective calculated-duty rate of 12.59%.
Is the U.S. a net importer of internal combustion engines? Yes — a net importer in 2025: $27.7B imported vs $8.8B exported (exports are 32% of imports).

About this data

Reference statistics derived from USITC published data. Not a customs ruling. MFN-Free and Special-rate fields describe statutory line coverage only; final entry liability requires origin, date, eligibility, exclusions and other transaction facts. Calculated Duties are statistical estimates, not a cash-collections ledger. Confirm classification, origin, program eligibility, and final entry liability with a licensed customs broker.

Last reviewed 2026-08-31.