A delivery business can finish the same number of stops, cover the same distance, and still end the week with less money. September's diesel prices make that painfully easy.
The U.S. Energy Information Administration put on-highway diesel at $6.285 a gallon for September 14, up from $5.257 on August 10. That's a 19.6% increase in five weeks. Regular gasoline rose 7.8% over the same period. A fleet's fuel mix now makes a substantial difference to its exposure. [1]
Five weeks, two very different fuel bills
The chart follows one consistent weekly EIA series. Diesel rose by $1.028 per gallon between the first and last observations; regular gasoline rose by $0.313. The brief diesel dip at the end of August did little to change the direction of travel. [1]
AP's September 4 reporting traced the pressure through freight, deliveries, and everyday goods. Axios also reported on the exposure of smaller operators. Those reports used daily market observations. Here, the calculations use weekly EIA prices throughout so that the comparison stays consistent. [3][4]
Weekly observations, August 10 to September 14, 2026. The vertical axis starts at zero. Prices are a dated snapshot.
View the underlying data
| Week of (2026) | Diesel, $/gal | Regular gasoline, $/gal |
|---|---|---|
| 2026-08-10 | 5.257 | 4.006 |
| 2026-08-17 | 5.454 | 4.049 |
| 2026-08-24 | 5.652 | 4.085 |
| 2026-08-31 | 5.599 | 4.071 |
| 2026-09-07 | 5.967 | 4.157 |
| 2026-09-14 | 6.285 | 4.319 |
What an unchanged route costs
Take a delivery operation buying 1,000 gallons of diesel a month. At the August 10 price, that fuel would cost $5,257. At the September 14 price, it would cost $6,285. The extra $1,028 buys no additional deliveries. This is a price sensitivity calculation for an assumed volume, rather than an observed customer bill.
The table holds consumption constant. It leaves out wages, maintenance, tolls, and software. It also assumes retail purchasing at the national benchmark. A fleet buying in bulk or using a negotiated fuel-card rate should substitute its actual paid price.
| Assumed gallons / month | At $5.257 | At $6.285 | Added monthly cost |
|---|---|---|---|
| 500 | $2,628.50 | $3,142.50 | $514.00 |
| 1,000 | $5,257.00 | $6,285.00 | $1,028.00 |
| 2,500 | $13,142.50 | $15,712.50 | $2,570.00 |
Illustrative volumes × EIA prices for August 10 and September 14, 2026. Taxes included. This is not a savings forecast.
Your depot's location matters
On September 14, EIA's regional diesel averages ranged from $6.027 on the Gulf Coast to $7.250 on the West Coast. A national average is useful for following the market. Route economics need the prices the fleet actually pays. [2]
For a dispatcher, the practical question is how much driving the day's orders require. Look for overlapping service areas, repeat journeys to the same neighbourhood, and long returns from the final stop. Check any proposed change against delivery windows and driver hours before treating the shorter distance as a saving.
The five PADD regions are shown. West Coast includes California. Retail prices include taxes.
View the underlying data
| EIA region | Diesel, $/gal |
|---|---|
| Gulf Coast | 6.027 |
| Rocky Mountain | 6.066 |
| East Coast | 6.158 |
| Midwest | 6.250 |
| West Coast | 7.250 |
Where Rotasal changes the calculation
Rotasal turns an order list into routes drivers can follow, with delivery windows, vehicle capacity, traffic, and driver constraints accounted for. Dispatchers get a plan for the day's work; drivers get their routes; customers get a tracking link. Those outputs give a team a practical way to reduce unnecessary driving while keeping its service commitments. [6][5]
Our reported results show 25–30% lower fuel spend compared with human dispatch, with 99.8% of stops arriving within their delivery window. These are Avernsys performance figures, separate from the U.S. market data above. The right test for a new fleet is a comparison using its own orders, vehicles, and delivery requirements. [5]
There is a useful piece of arithmetic here: offsetting the move from $5.257 to $6.285 would require roughly 16.4% less fuel, assuming the same delivery work and the later price. That threshold describes this price change. Whether a particular operation can reach it depends on the routes it runs today.
The record
Sources & method
Research checked September 18, 2026. Prices are nominal USD per U.S. gallon, including taxes. Percentage changes use August 10 as the base. The fuel reduction needed to offset the price increase is 1 − (5.257 ÷ 6.285). Monthly volumes are explicit examples. Public market observations and company-reported results describe different populations and have not been combined into a customer performance claim.
- U.S. gasoline and diesel retail prices U.S. Energy Information Administration · September 15, 2026
Weekly observations through September 14. USD per U.S. gallon, including taxes. Regular gasoline and on-highway diesel.
- Gasoline and Diesel Fuel Update U.S. Energy Information Administration · September 15, 2026
Regional diesel observations for September 14. Retail prices include taxes; fleet purchasing arrangements may differ.
- US diesel prices hit a record high, pushing up transportation costs Associated Press · September 4, 2026
Reporting on diesel costs moving through freight and delivery networks. Its daily AAA observations are separate from the weekly EIA series.
- Diesel price surges to all-time high, fueled by wars Axios · September 4, 2026
Additional reporting on fuel surcharges and smaller businesses' exposure to price volatility.
- Rotasal performance and product capabilities Avernsys · Reviewed September 18, 2026
Company-reported results: 25–30% lower fuel spend than human dispatch and 99.8% of stops within their delivery window. Customer identities and underlying order data are confidential. Results depend on the operation and are not a forecast for an individual fleet.
- Rotasal route optimization and delivery operations Avernsys · Reviewed September 18, 2026
Public product description: order uploads, delivery windows, vehicle and driver constraints, driver-ready routes, and integration with existing systems.
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