Diesel supply has declined by 8% compared to the prior year, triggering immediate operational and financial pressures across the U.S. trucking industry.
The reduction reflects tightening refinery output and shifting regional distribution patterns, with Western Gateway pipeline infrastructure still under development and California refining capacity remaining constrained. ’ SONAR data, diesel inventories fell to 23.7 million barrels in the week ending September 13, 2026 — the lowest level since early May 2026.
This supply contraction coincides with rising demand: freight volumes on the spot market increased 12% year-over-year in August 2026, while average diesel prices climbed to $4.28 , up 19% from the same period last year.
Impact on Carrier Operations
Trucking carriers are responding with measurable adjustments. A survey of 142 for-hire fleets conducted by SONAR in mid-September 2026 found that 67% reduced weekly mileage by an average of 145 miles, citing fuel availability and cost as primary constraints.
Additionally, 31% of respondents reported deferring scheduled maintenance due to budget reallocation toward fuel purchases, and 22% delayed planned equipment upgrades — including electrification pilots — until at least Q1 2027.
Will O’Donnell, senior analyst at FreightWaves, stated:
“The 8% diesel supply decline is not just a headline number — it’s compressing fleet utilization, raising per-mile costs by 11% on average, and forcing carriers to renegotiate contracts with shippers before Q4 2026.” — Will O’Donnell, Senior Analyst, FreightWaves
Regional Refining and Infrastructure Gaps
California refineries accounted for 18% of total U.S. diesel production in 2025 but contributed only 9% in the first eight months of 2026, Information Administration (EIA) data cited in the report. The Western Gateway pipeline project — intended to deliver refined products from Gulf Coast facilities to West Coast markets — remains scheduled for completion in Q3 2027.
Meanwhile, the U.S. East Coast experienced a 4.2% drop in terminal throughput for distillate fuels during July 2026, driven by unplanned outages at three major marine terminals in New Jersey and Virginia.
SONAR’s latest State of Freight Insights report, released on September 20, 2026, projects that diesel supply will remain below the five-year average through at least December 2026, with no meaningful recovery expected before Q2 2027.
Source: FreightWaves
Compiled from international media by the SCI.AI editorial team.
