Six weeks ago, diesel was a problem carriers thought they had a handle on. Spot rates were running 20-25% above last year, finally, after three years of a freight recession that had worn down margins to nothing, something was breaking the right direction. Owner-operators who'd spent those years white-knuckling through loads that barely covered fuel were starting to breathe again.
Then Iran.
The conflict disrupted oil flows through the Strait of Hormuz faster than anyone modeled, crude futures spiked, and diesel followed with a severity that caught even experienced carriers off guard. DAT put the national average at $5.375 per gallon the week of March 22-28, the highest weekly reading since late 2022. FTR called it the largest one-week diesel spike ever recorded, prices up 96 cents in seven days. California hit $7.22. For many carriers, costs are up more than $1.30 per gallon in three weeks. Not gradually, not in waves. All at once.
That's not a fuel surcharge adjustment. That's a business model stress test.
What the Shock Actually Costs at the Mile Level
The math is direct and unpleasant. ACT Research estimated that diesel costs spiked $0.25 to $0.30 per mile for truckload fleets in recent weeks. For a carrier running 100,000 miles per truck per year, a 25-cent increase in cost per mile adds $25,000 in annual fuel cost per unit, before accounting for deadhead miles, which don't generate revenue but burn diesel just the same.
TD Cowen analyst Jason Seidl was direct in a recent market note: one-way truckload carriers have the most exposure right now, given higher deadhead miles compared to dedicated operations. The velocity of the price change is its own problem, separate from the magnitude. Even carriers with fuel surcharges that reprice weekly are experiencing a near-term squeeze, because pump prices are moving faster than surcharges can catch up within a given week.
For small fleets and owner-operators, the exposure is more immediate. Spot market loads are typically priced all-in, without a fuel surcharge carveout. According to DAT's Dean Croke, small operators are lucky to recover half of higher fuel costs in their rates under these conditions. The difference comes out of margin that, for many, was already measured in cents per mile rather than dollars.
Jamie Hagen, owner of Hell Bent Xpress in South Dakota, told CNN he'd been planning to grow after refinancing equipment in anticipation of the market recovery. The Iran war started. Diesel, his largest operating expense, jumped more than 40% from pre-war levels. His costs are now up twenty cents per mile, wiping out the five cents per mile he typically earns. "We were already on the very breaking point to begin with," he said. "This is like the nail in the coffin."
The structural asymmetry is worth saying plainly. Large carriers running modern equipment with long-term contracts and fuel hedging in place absorb this differently than a small fleet owner buying diesel at $5.40 on a spot load priced all-in two days ago. C.H. Robinson's March market update noted that fuel pressure like this tends to redirect freight toward operators with better efficiency and tighter cost control. Cold comfort when you can't access hedging instruments or replace aging equipment mid-crisis.
How Carriers Are Actually Responding
Dean Croke spent time at the Mid-America Truck Show last week walking the floor and talking to carriers, and what he came away with matches the data. The responses are consistent across fleet sizes: find ways to cut deadhead, be more selective about load weight, and slow down.
The slowing down piece deserves a closer look, because the numbers are more significant than most drivers have actually run. Croke told The Trucker directly that at current diesel prices, dropping from 75 to 65 mph saves roughly 8 to 9 cents per mile. "It's like getting rates up five cents a mile by slowing down 10 miles an hour," he said. On a 600-mile day, that's $48 to $54 back in your pocket, without picking up an extra load, without negotiating a better rate, without doing anything except backing off the accelerator for a few hours.
The deadhead reduction piece is equally rational but harder to execute without the right lane relationships. Every empty mile costs fuel without generating revenue, and at $5.40 per gallon, those miles are dramatically more expensive than they were at $3.50. Carriers who've built networks with strong backhaul coverage in both directions are better positioned to actually execute on deadhead reduction. Those running transactional, spot-by-spot networks are finding the empty miles harder to eliminate.
Load selection is the third lever, and at current prices it has the most direct per-mile impact. A 40,000-pound load burns meaningfully more fuel than a 25,000-pound load. That was always true, but the cost difference at $5.40 per gallon is sharper than it was at $3.50. Carriers with the relationships and lane density to be selective about what they haul have an advantage that's hard to see in normal markets but shows up clearly on the P&L when fuel spikes.
Croke also noted that some carriers are simply declining unprofitable loads and sitting on the sidelines rather than running at a loss. That choice has market consequences. It tightens available capacity, which pushes spot rates higher. But the individual carrier math is straightforward: a load that doesn't cover fuel, driver pay, and fixed costs isn't worth hauling.
What Carriers Should Be Doing Right Now
The fuel shock is real, ongoing, and not resolved. EIA's March 2026 revised forecast projects a national average of $4.12 per gallon for the full year, up sharply from the February estimate of $3.43, and that forecast was built before prices reached their current peak. The practical question for carriers isn't whether diesel is expensive. It's what decisions made now protect margin while the market works through this.
Run the actual numbers on your cost per mile by lane. The national average means less than what you're paying in the specific lanes you actually run. Gulf Coast prices and Midwest prices diverged significantly during this spike. Some regions saw modest increases while others moved sharply. A carrier running Laredo to Dallas has a different fuel cost reality than one running Chicago to Atlanta. Know your lanes, know your actual fuel cost per mile in each one, and price accordingly.
Slow down systematically, not occasionally. The 8 to 9 cents per mile in savings Croke identified from dropping 10 mph isn't a tip. At scale, across a fleet, across a year, it's a material P&L line. A fleet with 10 trucks averaging 100,000 miles per year could recover $80,000 to $90,000 annually, roughly $6,700 to $7,500 per month, purely from the speed change. Set the policy. Track it. The savings are real and don't require any market conditions to change.
Audit your deadhead exposure by lane and by month. Carriers who haven't looked at their deadhead percentage recently may be surprised by what they find. Industry benchmarks suggest 10-15% as a reasonable target for over-the-road operations. Carriers running above that have a specific problem worth solving. Building relationships in lanes where backhaul freight is consistently available is the structural answer. Fuel card discounts and fuel stop optimization help at the margin but don't move the needle the way lane balance does.
Understand your fuel surcharge structure and its gaps. If you're running under contract with a fuel surcharge that reprices weekly, verify that the reset mechanism and benchmark are current. DAT data showed the national average dry van fuel surcharge jumped from 44 cents to 60 cents per mile in the two weeks following the strikes on Iran. That's a significant adjustment, but still lagging actual pump prices for carriers buying fuel mid-week. If your surcharge is indexed to a benchmark that moves weekly but you're buying fuel daily, you may be absorbing more than you realize between reset dates.
Be selective about spot freight, not just reactive. One of the clearest signals from Croke's analysis is that carriers who decline unprofitable loads rather than accepting them to keep moving are making the rational choice, and collectively, those decisions are tightening the market in ways that will support rate recovery. Running at a loss to maintain utilization is a cash flow problem dressed as a business strategy. Better to park a truck than burn diesel on a load that costs more to haul than it pays.
Build the shipper relationships that earn fuel surcharge access. The structural disadvantage for spot-dependent carriers is that they're negotiating all-in rates without fuel carveouts, while contract carriers are largely passing fuel cost increases through. The path from one to the other runs through shipper relationships, specifically relationships with shippers who understand that a carrier's fuel cost is a real input requiring a real mechanism to recover. Those conversations are easier to have now, while the market is moving, than they were during three years of a freight recession when shippers held all the leverage.
The Market Backdrop Is Actually Complicated
Here's what makes this fuel shock different from previous cycles: it's hitting at a moment when the freight market was already showing genuine signs of recovery.
Spot rates are running 20-25% above a year ago. The Manufacturing PMI jumped into expansionary territory, and new orders, a leading indicator for freight demand, was a major component of that expansion. Truck postings on DAT fell across all equipment types during the week of March 22-28, reaching their lowest Week 13 levels in at least 10 years of DAT data. Load-to-truck ratios are at multi-year highs.
The situation Croke described at MATS is unusual: a fuel shock hitting the market just as freight volumes are recovering could keep rates elevated even if fuel eventually moderates. That's a different dynamic than fuel spikes during slack markets, where carriers absorb the full hit without rate relief. The carriers who navigate this period without parking equipment and without running unsustainable loads will be better positioned when the shock resolves.
The ones who don't make it, the small fleets and owner-operators already operating at breakeven before the spike, will contribute to the capacity tightening that ultimately supports rate recovery for whoever's left.
That's a brutal market dynamic. But it's the one currently in motion.
Fuel is only one piece of the squeeze. For how it fits with carrier exits, equipment costs, and climbing rates, see how carrier exits, equipment costs, and rising rates fit together.
Questions about how to navigate fuel costs and carrier strategy in the current market? Let's talk.
📞 (931) 200-5601 | nfc@nationalfreightconnection.com
Sources: DAT Freight and Analytics, Dean Croke analysis and spot market data, March 2026; DC Velocity, Truck Freight Rates Tick Up Slightly to Start 2026; The Trucker, DAT Analyst Croke: Fuel Prices Have Sharply Elevated Operating Costs, March 2026; Logistics Management, Diesel Surge Tightens Truckload Capacity, Pushes Spot Rates Higher; Overdrive, Fuel's Surge Slows as Spot Rates React; Heavy Duty Trucking, U.S. Diesel Prices Hit $5.40, Top $7 in California; Trucking Dive, Diesel Price Surge Slows, but California Costs Still Swell; FTR Transportation Intelligence, Diesel Surge Reshapes the Freight Market, March 30, 2026; C.H. Robinson, Diesel Fuel Market Update, March 2026; CNN Business, America's Long-Haul Truckers Were Already Struggling. Then Came $5 Diesel, March 28, 2026; Best Yet Express, Diesel Fuel Prices and Freight Rates: How Rising Costs Are Impacting Trucking Margins in 2026; AllPro Now, 2026 Freight Market Update: Shippers Who Wait Will Pay More; EIA Short-Term Energy Outlook, March 2026; TransGlobal, Fuel Surcharge Update: Domestic Trucking and Ocean Carrier Increases Explained, March 14, 2026.