Overview

• Trump announced the measure on Truth Social after delaying an initial Oct. 1 start, setting Nov. 1 as the new effective date.
• The tariff is tied to a Section 232 investigation into trucks over 4,500 kilograms and parts, with the administration citing protection of U.S. manufacturers.
• Officials have not released implementing rules, leaving open whether the 25% levy is additive to existing tariffs or subject to exclusions.
• Mexico is most exposed, supplying about 82% of U.S. heavy‑truck imports, while vehicles meeting reported North American content thresholds of 64% could be exempt under pending rules.
• Truckmakers warn of higher costs and potential production shifts, noting earlier steel, aluminum and copper tariffs have already raised input prices; a separate Supreme Court case on country‑level tariffs is set for Nov. 5 but is not expected to alter this sectoral action.