The Energy Information Administration published its weekly on-highway diesel average on August 25. The national price was $5.652 a gallon for the week ending August 24, up 19.8 cents in seven days. That is the highest weekly reading of 2026. The same week last year, EIA had diesel at $3.754. (EIA Gasoline and Diesel Fuel Update)
Every brand shipping parcels pays for that number twice. Once in the freight itself, and once in a fuel surcharge line most people never look at.
Why the price is still climbing
The supply picture explains the run. EIA's Weekly Petroleum Status Report, released August 26, put distillate fuel inventories down another 2.2 million barrels for the week ending August 21, sitting about 14% below the five-year average for this time of year. Stocks landed at 103.4 million barrels. (EIA Weekly Petroleum Status Report)
Refineries are not holding anything back. The same report has them running at 97.4% of operable capacity, which is close to flat out, and distillate production still fell to an average of 5.1 million barrels per day. When utilization is already near the ceiling, there is no quick production answer to a supply gap.
Futures agree. NYMEX ULSD (the contract still listed as heating oil) settled at $4.3452 a gallon on Friday, August 28, up 1.55% on the day and up 91.44% from a year earlier. (Trading Economics) Retail diesel follows the futures market with a lag. EIA posts its next weekly price Monday, and the next inventory report lands September 2. Neither is likely to bring relief.
Two fees, and only one is on your calendar
Peak surcharges get all the attention because they are easy to plan for. They are published in advance and fixed in amount. You can put them in a spreadsheet in August and know roughly what December costs. We laid the major networks out side by side in the 2026 peak fee stack.
Fuel surcharges do not behave that way. They are assessed as a percentage of the base transportation charge, and they reset weekly against published fuel indexes. Nobody emails you when your fuel percentage moves.
That difference matters more than the amounts. A fixed fee you forgot to budget costs you a known number. A percentage you forgot to budget scales with your volume, and Q4 is when your volume peaks.
Two notes. The percentage on a published tariff is the same for every shipper, so it is not negotiable week to week. And agreements differ in which charges the fuel percentage attaches to, so read that section of yours before modeling anything.
Geography is doing most of the work
The regional spread in EIA's August 24 data is wide: California at $7.040 a gallon, the West Coast overall at $6.407, the Midwest at $5.636, and the Lower Atlantic at $5.350. That is nearly $1.70 between the priciest and cheapest regions in the same week.
Here is the part operators miss. Your fuel surcharge percentage does not drop because your package moved a shorter distance. The base rate does. Fuel is charged as a percentage of that base, so a lower zone produces a smaller fuel line in dollars. Shortening the trip is the only lever most brands actually control.
That is the case for where inventory sits. Our warehouse is in Canal Winchester, just outside Columbus, which reaches 90% of customers in two days by ground and puts 60% of the US and Canada population within 600 miles. Fewer miles per order means a smaller base rate, which means a smaller fuel line on the same invoice. More on the zone math is on our Columbus, Ohio location page.
What this means for your brand
If you ship 1,000 to 25,000 orders a month, four things are worth doing this month.
- Separate the fuel line from the base rate on your last 90 days of carrier invoices. Most brands have never calculated fuel as a share of total shipping spend.
- Rebuild the Q4 shipping budget with fuel as a variable. Model a range, not a single figure. A flat assumption carried over from spring is already wrong.
- Revisit your free shipping threshold. If you set it when diesel was under $4 a gallon, the math underneath it no longer holds. Raising a threshold in September is ordinary. Raising it on December 10 is a customer service problem.
- Look at your zone mix before you look at your rates. If most orders cross the country, a better rate card is a smaller fix than better inventory placement.
Our position: fuel is the line item most likely to break a Q4 shipping budget this year, and it is the one almost nobody has modeled. Peak surcharges are annoying but at least knowable. Fuel is not.
Want a read on what your zone mix costs at current fuel prices? Get in touch. We will run your order data against our ecommerce fulfillment zones and show the difference in dollars.
FAQ
How often do parcel fuel surcharges change?
Weekly. Carriers reset the percentage on a schedule tied to published fuel price indexes, which is why the fuel line can differ between two identical shipments in the same month.
Does a lower shipping zone reduce my fuel surcharge?
Not the percentage. It reduces the base transportation charge the percentage is applied to, so the fuel dollars come down. Moving inventory closer to customers is the practical fix.
Will fuel surcharges stack with holiday peak surcharges?
Both apply during the same window this year. How they interact on your specific invoice depends on your carrier agreement, so check which charges your fuel percentage attaches to rather than assuming.
What should I do if my Q4 budget assumed spring fuel prices?
Rerun it now. Use the current EIA weekly diesel price as your floor rather than a trailing average, and build a range above it. Adjusting a threshold in September is far cheaper than absorbing the gap in December.