Source: Supply Chain Dive. Summary and analysis by S2V Advisory.
What happened
Supply Chain Dive reported that the average U.S. diesel price passed $6.28 per gallon as of September 14, according to the Energy Information Administration. That is nearly 69 cents higher than on August 31, with gains of roughly 37 cents and then 32 cents in consecutive weeks. An analyst at DAT iQ linked the spike to escalating hostilities involving Iran and said some carriers are weighing whether to park trucks.
The article notes that diesel costs reach shippers through fuel surcharges pegged to the EIA’s weekly price, which is collected on Mondays and published on Tuesdays. That timing means contract surcharges can trail what carriers are actually paying at the pump. Carriers are also contending with soft freight volumes and regulatory changes affecting driver credentials, which together are tightening capacity and margins.
What it means for buyers
A fast fuel move exposes how freight contracts are really built. The base rate may be fixed, but the surcharge schedule decides what you pay when diesel jumps. Buyers should act before the next invoice cycle:
- Read your surcharge tables. Confirm the index, the peg price where the surcharge starts, the step size and the update frequency for each carrier. Small differences in the peg compound quickly at $6 diesel.
- Standardize across carriers. Different formulas across a carrier base make costs hard to compare and easy to overpay. A common method gives you a clean benchmark.
- Audit invoices against the index. Check that the surcharge billed matches the published EIA week the contract specifies.
- Protect capacity, not only price. With some carriers under margin pressure, a supplier that is squeezed too hard may drop your freight. Know which lanes depend on smaller carriers and have backups qualified.
- Update the budget. Share a revised fuel assumption with finance now rather than explaining a variance later.
Fuel will move again. Contracts that make its effect transparent and auditable keep the category under control. See our logistics and freight category page.