Diesel Above $6: Fuel Surcharges in Freight for 2026
Figures current as of October 7, 2026. Diesel prices change weekly, so always check the latest EIA release before applying any figure referenced in this article.
The U.S. Energy Information Administration's weekly on-highway diesel average reached $6.529 per gallon for the week of September 21, 2026.
That was the highest nominal reading in the history of the EIA series, which dates back to 1994, and well above the previous nominal record of $5.810 set in June 2022.
Prices have eased since then. The October 5 reading was $6.199 per gallon, the second weekly decline in a row, but still roughly $2.49 higher than a year earlier.
For freight brokers, shippers and carriers, moves of this size matter because fuel can quickly change the economics of a load.
Many U.S. truckload and LTL fuel surcharge programs reference EIA diesel prices, while Canadian and cross-border programs may use different benchmarks or carrier-specific tables.
For brokers in particular, rising fuel prices create two separate commercial considerations: what the customer pays for transportation and what the carrier is willing to accept to move the load. Those arrangements do not necessarily use the same fuel structure, unless the applicable contracts specifically require it.
Here is what the current diesel market means for freight pricing and what to look for when reviewing a fuel surcharge program.
What Happened to Diesel in 2026
A short timeline based on the EIA weekly U.S. on-highway diesel average:
February 23: $3.809
March 9: $4.859, up 96.2 cents in one week
April 6: $5.643
July 6: $4.578
September 7: $5.967
September 21: $6.529
October 5: $6.199
The broader backdrop has been disruption to oil production and exports in the Middle East.
In its October outlook, EIA estimated that crude oil production shut-ins in the region averaged 4.8 million barrels per day in September, down from 5.8 million barrels per day in August.
Diesel has also faced its own supply pressure.
EIA reported that East Coast distillate inventories were 32% below their five-year seasonal average in September and forecast inventories to remain around 20% below the 2021 to 2025 average through the winter.
Through October 5, the 2026 year-to-date weekly diesel average was approximately $5.04 per gallon. That is above the $4.989 full-year average recorded in 2022.
For trucking, the impact is significant.
ATRI's 2026 operational cost report put fuel costs at approximately $0.48 per mile in 2025, when diesel averaged around $3.66 per gallon.
At the October 5 national price of $6.199, a truck averaging 6.5 miles per gallon would spend roughly $0.95 per mile on fuel alone.
At the February 23 price, the same calculation would have been around $0.59 per mile.
That difference helps explain why fuel becomes such an important part of freight pricing when diesel moves quickly.
How Fuel Surcharges Are Commonly Calculated
Fuel surcharge structures vary by customer, carrier, lane and contract.
Two common approaches are per-mile formulas and percentage-based tables.
Per-Mile Formula
A typical formula looks like this:
Fuel surcharge per mile = (current fuel price - base fuel price) ÷ assumed MPG
For illustration, one commonly used legacy structure uses a $1.25 base price and a 6.0 MPG assumption.
Using the October 5 EIA price:
($6.199 - $1.25) ÷ 6.0 = approximately $0.825 per mile
On a 500-mile load, that would equal approximately $412 in fuel surcharge under that specific formula.
At the September 21 peak, the same formula would have produced approximately $0.88 per mile.
These figures are examples only. Actual contracts may use different base prices, MPG assumptions, indexes, mileage calculations or adjustment schedules.
Percentage-Based Fuel Surcharges
Another approach applies a percentage to the base transportation charge according to a published fuel table.
This structure is common in LTL freight, where carriers often maintain their own surcharge schedules.
As diesel rises or falls, the applicable percentage moves into a different band.
The important point is not that one approach is universally better. It is that everyone involved should understand which method applies to the shipment.
Why Fuel Matters Differently for a Freight Broker
For an asset-based carrier, fuel is a direct operating expense.
For a shipper, fuel is one component of transportation spend.
A freight broker sits between those two markets.
A broker may have one pricing structure with a customer and a separate agreement with the carrier moving the freight. For example, the customer relationship may include a defined fuel surcharge formula, while the carrier may quote an all-in rate based on current market conditions.
Those two commercial arrangements should not automatically be treated as identical.
What matters is that the broker understands both sides of the transaction and prices the load accordingly.
When fuel rises quickly, carrier expectations may adjust before a customer pricing agreement does. When fuel falls, the opposite can happen.
That makes visibility into current fuel prices, lane conditions and contract terms particularly important for brokers.
Where Fuel Surcharge Programs Can Create Problems
Several issues become more noticeable when diesel prices move as quickly as they have in 2026.
A Base Price That No Longer Matches the Rate Structure
The $1.25 fuel base remains common in some programs because it has been used historically.
There is nothing inherently wrong with that number if the underlying transportation rate was negotiated with the same structure in mind.
Problems can arise when the base used in the fuel calculation changes without a corresponding understanding of how the base freight rate was established.
The fuel surcharge and base transportation rate should be considered together rather than evaluated in isolation.
MPG Assumptions
A fuel surcharge formula may assume 6.0 MPG even though actual fuel economy varies significantly between trucks, equipment types, loads and operating conditions.
The assumption is normally a pricing mechanism, not an attempt to calculate the precise fuel consumption of each shipment.
What matters is that the agreed assumption is clear.
Weekly Versus Monthly Adjustments
Fuel prices can move significantly within a few weeks.
During the week of March 9, for example, the national EIA diesel average increased by 96.2 cents.
Using a 6.0 MPG assumption, that represents approximately $0.16 per mile in the example surcharge calculation.
A monthly fuel adjustment will naturally react more slowly than a weekly adjustment.
Neither structure is automatically incorrect. The important part is understanding how frequently the applicable program resets and which EIA publication date determines the price.
National Versus Regional Fuel Indexes
Regional fuel prices can differ substantially from the national average.
On October 5, EIA reported:
U.S. national average: $6.199
California: $8.082
Gulf Coast: $5.819
A national index therefore may not closely reflect the fuel environment of a particular regional lane.
For freight concentrated in specific regions, some agreements use regional EIA averages or other benchmarks instead.
Again, the appropriate structure depends on the commercial agreement and the type of freight being moved.
All-In Rates
Spot-market truckload rates are frequently negotiated as all-in prices.
There is nothing unusual about that.
The tradeoff is visibility.
When linehaul and fuel are combined, it becomes harder to determine how much of a rate movement comes from fuel and how much comes from capacity, seasonality, equipment availability or other market conditions.
For a broker, an all-in carrier quote may still be perfectly workable. The important thing is to understand the current fuel environment when evaluating that quote and when pricing the customer side of the shipment.
Deadhead and Accessorial Charges
Fuel programs can also differ in how they treat mileage and accessorials.
Some calculations apply only to loaded miles. Others may account for additional mileage.
Treatment of detention, stop charges and other accessorials also varies by contract.
These details should be clearly defined rather than assumed.
Five Things to Check in a Fuel Surcharge Program
A basic review does not require complicated software.
Start with the applicable customer or carrier agreement, recent freight invoices or settlements and the relevant fuel index.
1. Identify the Index
Determine whether the program uses the national EIA diesel average, a regional EIA price, a Canadian benchmark or another published index.
2. Confirm the Formula
Check the base fuel price, MPG assumption, percentage table, update frequency and rounding methodology.
3. Check Several Loads
Take several shipments from different weeks and recalculate the surcharge using the agreed methodology.
Small differences may come from rounding or mileage calculations. Larger differences may be worth reviewing.
4. Confirm the Effective Date
Determine which date establishes the applicable fuel price.
Depending on the agreement, that could be based on tender date, pickup date, invoice date or another defined point.
During periods of rapid price movement, the difference can become meaningful.
5. Review Mileage and Accessorial Treatment
Confirm which mileage is included and whether fuel applies to any non-mileage charges.
The agreement should determine the answer.
What High Diesel Can Mean for Capacity
Fuel surcharge mechanisms can reduce a carrier's exposure to rapid diesel-price increases, depending on how they are structured.
Not every truck has that protection.
Owner-operators and smaller carriers working heavily in the spot market may be more exposed to sudden fuel increases, particularly when market rates do not adjust as quickly as their operating costs.
Industry reporting in September highlighted the pressure higher diesel prices were placing on smaller operators and suggested that the broader truckload capacity correction remained underway.
For freight brokers, that matters beyond the fuel surcharge itself.
If operating costs remain elevated for an extended period, some carriers may become more selective about lanes, equipment utilization and minimum acceptable rates.
That can influence capacity availability and spot pricing even when the EIA diesel number begins moving lower.
Strong carrier relationships and current lane-level market information become especially valuable in that environment.
What About Shippers?
For shippers, fuel is one part of the total transportation cost.
When comparing carrier or broker proposals, it is important to compare the complete pricing structure rather than only the headline linehaul rate.
A lower base rate with one fuel formula is not automatically cheaper than a higher base rate with another.
The same applies to all-in pricing.
The clearest comparison is the expected total transportation cost under the actual terms being offered.
For brokers, being able to explain that structure clearly can also help customers understand why freight pricing may change even when the underlying lane has not.
What the Forecasts Say
EIA's October 6 Short-Term Energy Outlook expects Brent crude oil to average approximately $105 per barrel in the fourth quarter of 2026 and $84 in 2027.
It also expects U.S. retail diesel prices to average approximately $4.50 per gallon in 2027 as Middle East production gradually recovers.
But forecasts can change quickly.
Only one month earlier, EIA's September outlook projected Brent crude to average $67 per barrel during the second half of 2027.
That difference is a useful reminder of how uncertain energy markets remain.
For freight companies, forecasts are useful for planning scenarios. They are much less useful as a basis for assuming exactly where diesel will be several months from now.
The Bottom Line
Fuel prices are moving enough in 2026 to have a meaningful effect on freight economics.
For shippers and carriers, that makes clearly defined fuel terms increasingly important.
For freight brokers, the issue is slightly different.
Brokers need to understand the customer pricing structure, the carrier's current market expectations and the fuel environment affecting both sides of the shipment.
Those arrangements may be connected, but they are not necessarily identical.
Clear contracts, current market data and transparent communication help reduce surprises when diesel moves quickly.
And with diesel moving from $3.809 in February to a record nominal $6.529 in September before easing to $6.199 in early October, 2026 has provided a strong reminder of just how quickly those conditions can change.
Sources
U.S. Energy Information Administration, Gasoline and Diesel Fuel Update, weekly U.S. and regional on-highway diesel prices, data through October 5, 2026: https://www.eia.gov/petroleum/gasdiesel/
U.S. Energy Information Administration, Short-Term Energy Outlook, October 6, 2026 and September 9, 2026 editions: https://www.eia.gov/outlooks/steo/
American Transportation Research Institute, An Analysis of the Operational Costs of Trucking: 2026 Update, July 2026: https://truckingresearch.org
FreightWaves, industry reporting and carrier commentary from the September 2026 Morgan Stanley Laguna conference, September 17, 2026
This article is provided for general informational purposes for logistics professionals. It is not legal, tax, financial or contractual advice, and it is not a recommendation to use any specific pricing or fuel surcharge structure. Fuel prices, forecasts, contract terms and market conditions vary and change frequently. Figures referenced here reflect sources available as of October 7, 2026.