A Houston shipper priced a Houston-to-Chicago dry van lane in January. The CFO approved the number. Same carrier, same contract, same equipment, and by September that same load costs materially more. The linehaul never moved. The fuel surcharge did.
If you are doing freight shipping Houston in the back half of 2026, the fuel surcharge is the line item that has moved most, and it is the line item almost nobody verifies. Most shippers approve it. That is not the same thing as verifying it.
What Actually Happened to Gulf Coast Diesel
Start with the number, because the number is not in dispute. The EIA weekly Gulf Coast No. 2 diesel retail series put PADD 3 on-highway diesel at $6.027 per gallon for the week ending September 14, 2026. The same series read $3.172 on January 5, 2026, and $3.389 in mid-September 2025. That is roughly a 90% move year-to-date and roughly 78% year-over-year, in the region that refines the fuel.
The move was not gradual. Gulf Coast diesel went from $3.598 to $4.627 in the single week ending March 9, 2026 — a dollar a gallon in seven days. It has been volatile and elevated ever since. The Dallas Fed energy indicators track the refining-margin side of this; the short version is that refineries have been running near the top of their operable utilization while distillate inventories drew down, which is what a record crack spread looks like from the shipper side of the invoice.
There is a second, local wrinkle. Gulf Coast refineries carry a heavy turnaround schedule in the September-to-November window, and that window overlaps hurricane season. Houston is both the origin of much of the nation’s diesel and a freight market that pays for it.
Why Houston Shippers Have Less Leverage Than They Think
Fuel is only half the problem. The other half is that Houston is a headhaul market with a tight outbound truck supply.
Per Port Houston’s published statistics, the Houston Ship Channel complex is the largest U.S. port by waterborne tonnage, Port Houston handles roughly 75% of U.S. Gulf Coast container traffic, and holds about 97% of Texas container market share. Container volumes have set records through 2026. Every one of those boxes needs a truck.
FreightWaves has repeatedly flagged Houston outbound tightening through its SONAR headhaul index, where inbound import volume converts into outbound tender pressure and rejection rates climb. When you are the party asking for a truck in a headhaul market, you do not get to be difficult about accessorials. So most Houston shippers stop asking.
The Manual Process Almost Everyone Is Running
Here is what the current workflow actually looks like at a mid-market shipper doing 30 to 60 loads a month out of Houston:
Order drops in the ERP. A coordinator pulls up the carrier portal or emails three reps for a rate. A number comes back, usually as linehaul plus fuel plus accessorials, sometimes as one blended figure. The coordinator books it. Three weeks later the invoice hits AP. AP matches the invoice total against the PO, not against the fuel index. If the total is within tolerance, it gets approved. If it is not, someone emails the carrier and usually loses.
Nobody in that chain knows which week of EIA data the carrier applied, what baseline price the contract specified, what miles-per-gallon divisor was assumed, or whether the surcharge was pegged to the national DOE average or to a regional index. That information exists — it is in a PDF someone signed eighteen months ago. It is just not in a system that can act on it.
That is the whole failure. The contract terms are language; the invoice is data; nothing reconciles the two.
The Architecture We Would Build Instead
Here is the architecture we would build for a Houston shipper. It is not exotic. It is four connected steps where there are currently four disconnected humans.
1. Store the surcharge terms as structured data. Every carrier agreement gets parsed once into fields: index source (EIA national vs. PADD 3), update cadence, baseline price per gallon, MPG divisor or bracket table, and effective dates. This lives in the TMS, not in a filing cabinet. We use FreightPOP as the TMS and API layer for this, with free API setup for qualified shippers.
2. Pull the index automatically. EIA publishes weekly, on a schedule, free. A job pulls the relevant series every Tuesday and writes it to the same record the contract terms live in. No human transcribes a fuel price ever again.
3. Compute expected fuel at rate time, not invoice time. When the ERP requests a rate, the system returns linehaul and an independently computed expected surcharge. Now the quote your CFO approves and the invoice your AP team pays are derived from the same formula.
4. Flag variance, route exceptions to a human. Invoice arrives, system compares actual FSC to expected FSC, and anything outside tolerance goes to a queue. Everything inside tolerance auto-approves. Your people stop reviewing invoices and start working disputes that are actually worth working.
That is the same pattern behind every system we build: connect the data, automate the deterministic part, and put humans where judgment actually pays. It is the core of how we run managed transportation programs and what our logistics API and automation consulting work is generally pointed at.
The Economics
Illustrative example — run your own numbers. Take a common truckload surcharge formula: (fuel price minus baseline) divided by assumed MPG, applied per mile. Assume a $1.25 baseline, a 6.0 MPG divisor, and a Houston-to-Chicago run of roughly 1,090 miles.
At January 2026 Gulf Coast diesel of $3.172, that is ($3.172 – $1.25) / 6.0 = $0.320 per mile, or about $349 of fuel surcharge per load. At the September 14, 2026 price of $6.027, the same formula gives $0.796 per mile, or about $868 per load. A delta of roughly $519 on a lane where you negotiated nothing and changed nothing.
At 40 loads a month, that is about $20,800 a month of pure index movement. Those are real EIA prices run through a standard formula, but the baseline, the divisor, and the mileage are assumptions — your contract almost certainly uses different ones, which is exactly the point. If you cannot state your own three inputs from memory, you cannot audit your own invoices.
The upside here is not that automation makes diesel cheaper. It does not. The upside is that the difference between the surcharge you owe and the surcharge you are billed becomes visible, and visible errors get recovered. On full truckload, where a single point of variance is hundreds of dollars a load, that visibility pays for the build quickly.
Where This Argument Is Weak
Two honest admissions.
First, most carriers are not cheating you. Regulatory precedent is long-standing that surcharges are cost recovery, not a profit center, and shippers have won on that principle — Railway Age has covered the ongoing rail fuel surcharge litigation where exactly that argument carried. But the disputes that get litigated are rail, at scale, with counsel. In day-to-day truckload, most variance we see is not fraud. It is stale baselines, wrong index week, and formulas nobody updated. Build this expecting recovery from sloppiness, not from malice, and you will size the ROI correctly.
Second, if you ship fewer than about 15 loads a month, do not build this. The engineering and maintenance cost will exceed the recovery. Put your three surcharge inputs in a spreadsheet, check five invoices a quarter by hand, and spend the effort on lane strategy instead. Automation is leverage on volume. Below a volume threshold it is just expensive tidiness.
The Houston Playbook
If you want to move on this without rebuilding anything, start here:
Pull your top three carrier contracts and find the fuel language. Write down index source, baseline, and divisor for each. If they differ, you have three different exposures and one blended expectation, which is how variance hides.
Check whether you are pegged to the national DOE average or to a regional series. Gulf Coast diesel and the national average do not move together, and Houston shippers are sometimes billed on an index that has nothing to do with the fuel their trucks burn. That is not necessarily wrong, but you should know which one you signed.
Audit ten invoices by hand against the published EIA number for the correct week. If your variance is under 1%, your process is fine and you should stop here. If it is over 3%, you have found a recurring leak and it has been running for as long as your contract has.
Reconsider where the freight originates. Some of what looks like a Houston fuel problem is a network problem. If you are paying Gulf Coast surcharges to serve Midwest and Northeast customers, a second distribution node changes the zone math before it changes the fuel math. We place shippers with 3PL partners in Kansas City, North Jersey, and Dallas based on where their customers actually are — we own no warehouses, so we have no reason to recommend the wrong one.
The through-line is the same one we come back to constantly: why are your people still doing this manually? A fuel index is a published number on a fixed schedule. A contract formula is arithmetic. Neither requires a human. The judgment call — whether to dispute, whether to renegotiate, whether to re-route the freight entirely — absolutely does. That is where your people should be.
Get a Free Freight and Logistics Review
Tell us what you are shipping out of Houston and we will show you exactly where the savings are — including a read on your current fuel surcharge terms. No consultants. No commitments. Just straight answers from operators who have been doing this for 20+ years. Call (866) 854-5341 or use the form below.