September
Diesel didn’t cool off in September. Here’s where the market stood – and what it means for carrier margins heading into summer.
September didn’t give carriers a breather. The national average climbed to $6.29, $0.783 above where August closed and 67.82% above September 2025, and all four weeks of the month priced above $5.00, bringing the 2026 total to 25. Monthly-reset carriers are now two resets behind a rising market: September’s rate locked to August’s average, and the pump moved well past that number before the month was half over. Quarterly-reset carriers have been shielded by Q2’s elevated average, but Q4 resets will absorb everything that has built since late July in a single step. Heading into October, any surcharge not tied to a live weekly index is paying September’s fuel bill with last month’s math.
Source: EIA Weekly U.S. No 2 Diesel Retail Prices | magnustech.com