- U.S. on-highway diesel prices rose from $3.477 to $5.348 per gallon between early January and early August 2026, a 53.8% increase — the largest January-to-August jump in the 32 years of weekly EIA data since 1995.
- Diesel peaked at $5.643 on April 6 (62.3% above January), pulled back 18.9% by early July, then climbed again into August.
- Distillate fuel oil inventories fell 17.1% over the same period, from 129.3 million to 107.2 million barrels.
- For a typical long-haul combination truck (60,205 miles per year at 6.91 MPG), the price increase adds roughly $16,300 per year in fuel cost alone.
These are national averages—your actual fuel cost depends on your specific vehicle and location.
Calculate Your Exact Cost01 The 2026 Diesel Spike: What Happened
The national average price of on-highway diesel fuel opened 2026 at $3.477 per gallon the first week of January. By the first week of August, it stood at $5.348—an increase of 53.8% in seven months.
U.S. Energy Information Administration, Weekly U.S. No 2 Diesel Retail Prices, week of Jan. 5, 2026 and week of Aug. 3, 2026Diesel rose faster and further than gasoline did over the same period. Prices climbed sharply starting in early March, reaching a peak of $5.643 on April 6—62.3% above the January level, and roughly a month earlier than gasoline's May peak. Diesel then retreated through late spring and early summer, falling 18.9% to a low of $4.578 on July 6, before climbing again through July into early August.
U.S. Energy Information Administration, Weekly U.S. No 2 Diesel Retail Prices, weekly series, January–August 202602 How Unusual Is This?
Since 1995, the median January-to-August change in diesel prices has been +5.7%. 2026's 53.8% increase is not just unusual—it is the largest January-to-August jump in the entire 32-year series, surpassing even 2022's 36.5% (driven by the aftermath of Russia's invasion of Ukraine) and 2008's 33.4% (the pre-financial-crisis oil price spike).
Calculated from U.S. Energy Information Administration, Weekly U.S. No 2 Diesel Retail Prices, 1995–2026. Comparison uses the first available weekly price in January and August of each year.| Rank | Year | Jan-to-Aug Change |
|---|---|---|
| 1 | 2026 | +53.8% |
| 2 | 2022 | +36.5% |
| 3 | 2008 | +33.4% |
| 4 | 2021 | +27.4% |
| 5 | 2005 | +24.5% |
| 6 | 2006 | +22.9% |
| 7 | 2004 | +20.7% |
| 8 | 1999 | +19.8% |
| 9 | 2011 | +16.9% |
| 10 | 2009 | +14.6% |
Every other year in the top 10 was tied to a specific, well-known macroeconomic shock: the 2008 financial crisis, the 2021 post-COVID demand recovery, or the 2022 invasion of Ukraine and its effect on global energy markets. 2026 is the first time in this 32-year record that an increase of this size has occurred without one of those widely-recognized triggers preceding it.
Calculated from the same 1995–2026 EIA weekly diesel price series; comparison of year-over-year context for each top-10 year.03 What's Driving It: Distillate Inventories
U.S. distillate fuel oil inventories (the category that includes on-highway diesel) fell from 129.3 million barrels in early January 2026 to 107.2 million barrels by the end of July—a decline of 17.1%. Unlike gasoline stocks, which held roughly steady through January and February before declining, distillate stocks began falling almost immediately in mid-January, well before diesel prices started climbing in March.
U.S. Energy Information Administration, Weekly U.S. Ending Stocks of Distillate Fuel Oil. Comparison of week of Jan. 2, 2026 to week of Jul. 31, 2026 (the most recent data available at time of writing).04 The Cost to Trucking and Freight
Diesel powers the large majority of U.S. freight transportation, so a price move of this size has direct consequences for trucking costs. The FHWA's Highway Statistics data puts the average combination truck (a tractor-trailer, the standard long-haul freight vehicle) at 60,205 miles traveled per year, averaging 6.91 miles per gallon—which works out to about 8,710 gallons of diesel consumed annually.
FHWA, Highway Statistics 2022, Table VM-1: Annual Vehicle Distance Traveled and Related Data. Combination trucks: average miles traveled 60,205; average miles traveled per gallon 6.91; average fuel consumed per vehicle 8,710 gallons (internally consistent within the same table).At January's $3.477/gallon, fueling that truck for a year cost approximately $30,285. At August's $5.348/gallon, the same truck costs approximately $46,581 to fuel—an increase of roughly $16,300 per truck per year, before any other operating costs. For fleets operating hundreds or thousands of trucks, that per-vehicle increase compounds into a substantial new cost line, one that historically gets passed through to shipping rates and, eventually, consumer prices for goods that travel by truck.
Calculated: 8,710 gallons × $3.477/gal = $30,285; 8,710 gallons × $5.348/gal = $46,581; difference = $16,297, rounded. Uses the same FHWA VM-1 combination-truck fuel-consumption figure as above.Curious how fuel price changes affect your own vehicle's annual cost?
Use the Calculator05 How This Compares to Gasoline
Gasoline prices also spiked in 2026, rising 44.0% from January to August—the second-largest such increase since 1994. Diesel's 53.8% increase was even larger, and unlike gasoline's second-place finish, diesel's move is the single largest January-to-August increase on record in its own 32-year series. Both fuels show the same broad pattern: a sharp climb in the spring, a partial summer retreat, and a renewed climb heading into August—consistent with both fuels being drawn from the same underlying crude oil supply chain, even though their specific inventory levels and price timing didn't move in perfect lockstep.
See Why Gas Prices Spiked in 2026 for the full gasoline-side data, inventory analysis, and regional breakdown.06 Data Sources
- U.S. Energy Information Administration: Weekly U.S. On-Highway Diesel Fuel Prices, 1995–2026. eia.gov
- U.S. Energy Information Administration: Weekly U.S. Ending Stocks of Crude Oil and Petroleum Products (Distillate Fuel Oil). eia.gov
- Federal Highway Administration: Highway Statistics 2022, Table VM-1: Annual Vehicle Distance Traveled and Related Data. fhwa.dot.gov