Manufacturing Input Costs Hit Four-Year High at 84.6
ISM prices-paid gauge climbed for the fourth straight month — the highest reading since May 2022 — as manufacturers face sustained cost pressure that flows through to freight rates and fuel surcharges.
Why are manufacturing input costs climbing?
The Institute for Supply Management's gauge of prices paid for manufacturing inputs climbed to 84.6 in April 2026 — a four-year high and the fourth consecutive monthly increase. The reading marks the highest level since May 2022, when pandemic-era supply shocks and fuel spikes pushed input costs to similar territory.
The ISM prices-paid index measures what manufacturers report paying for raw materials, components, and energy. A reading above 50 signals rising costs; 84.6 means the vast majority of surveyed manufacturers saw input prices climb month-over-month. The April figure continues a climb that began in January, when the index sat in the mid-60s.
What drives the cost spike
Manufacturing input costs track closely with diesel, steel, plastics, and commodity prices — all of which have climbed sharply since late March as the U.S.-Iran conflict in the Strait of Hormuz pushed Brent crude above $100 for eight straight weeks. Diesel prices followed: the national average hit $4.12 per gallon in late April, down slightly from a $5.46 peak earlier in the month but still $1.93 higher year-over-year.
Steel and aluminum — two of the heaviest inputs for durable-goods manufacturers — have also climbed as energy costs raise smelting and transport expenses. Plastics, derived from petroleum feedstocks, move in lockstep with crude. When manufacturers pay more for these inputs, they pass costs downstream through higher wholesale prices, tighter inventory turns, and fuel surcharges on outbound freight.
The freight connection
Higher manufacturing input costs show up in two places for small fleets: fuel surcharges and spot-rate pressure. When manufacturers face rising costs, they lean harder on logistics partners to absorb fuel volatility through FSC adjustments rather than fixed contract rates. That shifts risk to carriers, especially owner-operators running spot loads without negotiated surcharge floors.
At the same time, sustained input-cost pressure often signals stronger manufacturing output in the months ahead — factories that are paying more for materials are typically running lines, not idling them. The ISM report's headline noted U.S. manufacturing "holds up" despite the cost spike, suggesting production has not collapsed under the weight of higher inputs. That production activity generates freight demand, which has helped push spot rates to a 12-year high — flatbed hit $2.66 per mile in late April, the highest since 2014.
How long the cost pressure lasts
The four-month climb in the ISM prices-paid gauge mirrors the timeline of the Hormuz conflict, which began choking oil flows in late December 2025 and escalated sharply in March 2026. As long as crude holds above $100 per barrel, input costs for manufacturers — and diesel costs for carriers — will remain elevated. Oil slid to $108.51 on April 30, down from a $110.44 peak earlier in the week, but still double the $54 per barrel average of 2019.
If the conflict de-escalates and crude falls back below $90, the ISM gauge would likely retreat into the 60s within two months — the index moves quickly in both directions. If crude stays elevated through summer, manufacturers will continue passing costs through the supply chain, keeping upward pressure on freight rates and fuel surcharges.
What it means for a 10-truck fleet
A 10-truck fleet running 1,200 miles per week per truck at 6.5 mpg burns roughly 1,846 gallons of diesel per week. At $4.12 per gallon, that's $7,606 in weekly fuel cost. The $1.93 year-over-year increase in diesel adds $3,562 per week — $185,224 annually — compared to April 2025. Fuel surcharges tied to the DOE index have climbed in parallel, but many spot loads and short-term contracts lag the actual pump price by two to four weeks, leaving carriers exposed during rapid spikes.
Higher manufacturing input costs also mean tighter inventory management and shorter lead times for shippers, which can translate to more last-minute spot tenders and detention as factories juggle costlier materials. Fleets running manufacturing lanes — automotive parts, steel coil, machinery — should expect continued fuel volatility and rate negotiation pressure through Q2 2026, with the timeline hinging on crude oil's path.
