The 2027 engine

From January 2027 a new heavy truck sold in the United States must meet the EPA's 2027 standard for nitrogen oxides, 0.035 grams per horsepower-hour. The rule was finalised in 2023. In November 2025 the agency said it would not delay the date and would not change the number. What it proposed to change this year is the fine print around the number: useful life, warranty, the penalties for non-conforming engines and the inducements that stop a truck with a faulty emissions system. The comment period on those changes closed in early September. The engine makers' association told the agency the amendments would make the rule "more implementable for manufacturers and more cost-effective for trucking fleets." A truck dealer told it that "imposing thousands of dollars in nonconformance penalties on otherwise proven, reliable engines is not a practical solution." No final rule has been published.

The pre-buy, by the numbers

Fleets that did not want a first-year 2027 engine bought 2026 trucks instead, and they bought a great many. FTR counts the 2026 order season, September 2025 to August 2026, at 350,677 class 8 orders, 39 percent more than the season before. The peak was June, at 30,500 orders, 241 percent above June 2025; July brought 22,000 and August 18,200. ACT Research's final August count was lower, 16,951, up 32 percent on the year but down 34 percent on the month once adjusted for the season. FTR's Dan Moyer: "August marks the close of the 2026 order season and the effective end of the EPA 2027 NOx pre-buy."

The factories cannot build what has been ordered any faster. ACT reported second-half 2026 backlogs "oversubscribed by approximately 35,000 units" at the end of July. In August Transport Topics described 2026 production as essentially sold out and the 2027 order boards as largely unopened. September's preliminary orders, published on 2 October, came in at 18,700, down 9.5 percent on the year, under the headline "Regulatory Uncertainty Weighs on September Preliminary Class 8 Net Orders." ACT's Carter Vieth: "The 2027 regulatory engine transition is clearly impacting order seasonality this year." Some manufacturers are "not fully opening their 2027 orderboards."

What the next truck will cost

Estimates reported by FTR put a fully compliant 2027 engine at an 8,000 to 12,000 dollar upcharge from the manufacturer, and a non-compliant engine sold under penalty at 6,000 to 7,000 dollars. That sits on top of what tariffs have already done. A 25 percent tariff on imported medium- and heavy-duty trucks and parts has applied since 1 November 2025, with USMCA-qualified vehicles exempt and an offset of 3.75 percent for trucks assembled in the United States. FTR's Moyer put class 8 build-cost increases at 15 to 24 percent since the start of 2025. In March Daimler Truck's chief financial officer said "the probability of increasing pricing slightly or potentially increasing tariff surcharges over the year has increased."

The parts counter felt it first. The Decisiv and TMC service benchmark, reported in May, found components "20% to 30% more expensive to replace than they were before": a set of injectors from about 1,800 dollars to 2,200, a turbocharger from about 900 to 1,100. A reconditioning budget written in 2024 is a fifth to a third light.

The ceiling and the floor

For a used truck two forces now pull in opposite directions, and they pull on different trucks. The ceiling is the price of a new one. A buyer who cannot get a 2026 build slot and will not pay the 2027 premium has one place to go: a clean 2023 to 2026 tractor with a pre-2027 engine. Everything that raises the new price, the engine, the tariff, the surcharge, raises what that buyer will pay for the used one.

The floor is supply. Every 2026 truck delivered in the fourth quarter displaces a truck a fleet was running, and the pre-buy fleets were running 2021 to 2023 tractors. J.D. Power's September edition expects trades to "increase in Q4 as backloaded new truck deliveries increase." Cass noted class 8 tractor sales above replacement levels in July and August for the first time in eighteen months. Those trades land in the segment where Sandhills counts sleeper inventory down 42 percent on the year, which is why it is scarce today and why it will be less scarce by spring.

The pre-buy pulled a year of demand forward. The trades it generates arrive over the next two quarters.