Fuel costs don't move uniformly across the country, and any fleet operator who has compared a fuel card statement from a California route against one from Texas already knows this instinctively. The Petroleum Administration for Defense Districts (PADDs) split the US into five regions with genuinely different refining capacity, pipeline access, and regulatory environments, and those structural differences are showing up in the numbers again as 2026 pricing settles at levels well above where the year started.
Why PADD Geography Still Matters for Fleets
The PADD system was created during World War II to manage petroleum distribution, but it remains the most useful lens for understanding why your fuel spend varies by lane. PADD 3 (Gulf Coast) is home to the bulk of US refining capacity and benefits from proximity to production and export infrastructure. PADD 5 (West Coast) is comparatively isolated: limited pipeline connectivity to the rest of the country, stricter fuel specifications, and a smaller pool of refineries mean that any supply hiccup shows up faster and larger in the price at the pump.
That structural gap hasn't gone away. If anything, recent commentary from oil markets suggests it's becoming more persistent. Analysts have flagged that refining capacity nationally is strained enough that gas prices could stay elevated even if crude oil prices ease, because refining, not just crude, is now the binding constraint. For fleets, that means the usual assumption that "oil comes down, pump prices follow" may not hold as cleanly as it has in past cycles.
The National Picture: A Compressed but Real Pullback
Nationally, diesel averaged $3.52 in January before peaking at $5.59, a 59% run-up, and now sits at $4.97. Regular gasoline followed a similar arc: $2.70 in January, a peak of $4.35 (+61%), and a current price of $3.95. The pullback from peak is real, but both fuels remain far above where the year began. For budgeting purposes, treat the January figures as historical reference points, not a target to plan around. The new baseline is meaningfully higher.
Gulf Coast (PADD 3): Still the Cheapest Region, But Not Immune
PADD 3 continues to offer the lowest absolute prices among the regions with published data here, and that's consistent with its refining density. Diesel in the Gulf Coast started the year at $3.23, peaked at $5.20 (a 61% increase, actually a steeper percentage swing than the national average), and now sits at $4.42. Gasoline moved from $2.41 to a peak of $3.98, a 65% jump, before settling at $3.48.
The lesson for fleets running Gulf Coast lanes: don't assume regional cost advantage means regional price stability. PADD 3 had the largest percentage swings in this dataset for both fuels, even though it remains the cheapest region in absolute terms. Refining capacity that normally serves as a buffer for the rest of the country can just as easily become a transmission point for volatility when supply is tight or geopolitical risk spikes.
Texas: A Bellwether Worth Watching Separately
Within PADD 3, Texas gasoline data tells a similar story at the state level: January average of $2.37, a peak of $3.96, and a 67% increase, before settling at $3.55. That's the steepest percentage move of any figure in this data set. Fleets with significant Texas mileage should treat the state's historically low absolute prices as a partial hedge, not full protection, against national volatility events.
West Coast (PADD 5): The Most Expensive Region, Consistently
If your fleet runs any meaningful mileage in California, Oregon, Washington, or the broader West Coast market, you already know this region operates on a different price curve entirely. PADD 5 diesel started the year at $4.18, peaked at $6.72 (+61%), and now sits at $5.81. Gasoline moved from $3.39 to a peak of $5.25 (+55%) and now sits at $4.81.
Notably, PADD 5's percentage increases were roughly in line with the national average (in gasoline's case, slightly below it), even though the absolute dollar figures are dramatically higher. That's the core West Coast dynamic: the region doesn't necessarily see worse volatility in percentage terms, but it compounds on a much higher price base, so every percentage point costs more in real dollars.
California: The Extreme Case
California deserves its own line item because it consistently posts the highest fuel prices in the country. Diesel ran from a January average of $4.66 to a peak of $7.42 (+59%), now at $6.59. Gasoline moved from $4.01 to a peak of $5.97 (+49%, the smallest percentage swing in this data set) and now sits at $5.41.
California's gasoline market didn't swing as violently in percentage terms as the Gulf Coast or Texas did. But the absolute cost impact is still the largest anywhere in the country, simply because the starting point was already so high. A fleet paying $5.41 per gallon for gasoline is absorbing a materially different cost structure than one paying $3.55 in Texas, even if the underlying volatility profile looks similar on paper.
What's Driving the Persistent Spread
A few forces from recent market coverage help explain why these regional gaps are proving sticky rather than transitory:
Refining capacity constraints. Multiple market analysts have pointed out that US refining capacity is running with little slack. Even when crude oil prices retreat, refined product prices, the ones that actually show up at your pump, may not follow proportionally, because the bottleneck has shifted downstream.
Geopolitical risk premium. Escalating tension tied to US-Iran dynamics has pushed oil markets sharply higher on a weekly basis, with some coverage citing gains near 10% in a single week amid intensifying attacks. Separately, reports of Iran-linked LPG tankers reversing course and taking evasive routes to avoid a US naval blockade underscore how quickly supply-chain risk can escalate in energy-adjacent markets. None of this is abstract for fleets. It's the kind of headline risk that can move diesel and gasoline futures within a trading session, well before it reaches a regional average.
Supply-side offsets are modest. On the positive side, Libya's National Oil Corporation and OMV have declared a new oil discovery commercially viable, with production revival gaining pace. It's a reminder that new supply does continue to come online even amid disruption. But new discoveries take time to reach markets and rarely offset near-term geopolitical shocks affecting refined products in the US.
Domestic policy friction. Away from the pump, energy infrastructure fights are intensifying in ways that could affect regional power and fuel costs longer-term. In Virginia, a prominent state senator has pushed back publicly on unchecked data center expansion, arguing that public frustration over the associated energy demand cuts across political lines. Fleets with East Coast exposure should watch these regional energy-policy fights, since they can eventually influence local fuel and power cost structures even when they start as electricity debates.
Practical Steps for Fleet Operators
Given this environment, a few operational habits are worth reinforcing:
- Map your lanes to PADDs, not just states. If your routes cross PADD 3 into PADD 5, build separate cost assumptions for each leg rather than blending them into a single national average.
- Re-baseline your budget off latest prices, not January figures. Every region above remains substantially higher than where it started the year, even after pulling back from peak. Budgeting off outdated averages will understate your real exposure.
- Watch refining capacity commentary, not just crude oil headlines. As several analysts have noted, refined product prices can stay elevated even if crude eases, because the constraint has moved downstream. Don't assume a drop in oil headlines automatically means relief at the pump.
- Build in geopolitical headroom. Given how quickly oil has moved on Iran-related developments in recent weeks, fleets with thin margins should stress-test budgets against another rapid double-digit percentage swing, not just gradual drift.
This is exactly the kind of environment where a fuel price cap earns its keep. FuelAnchor's model locks in a ceiling price by region, so if PADD 5 or California spikes again on the next geopolitical shock, your budgeted cost per gallon doesn't move: you get the upside if prices ease, and protection if they don't. For fleets managing multi-PADD operations, that kind of regional certainty can matter more than chasing the cheapest spot price lane by lane.
The Bottom Line
Regional fuel price spreads aren't a temporary artifact of this year's volatility. They're structural, rooted in refining geography that has existed for decades and is now being stress-tested by tighter capacity and heightened geopolitical risk. Understanding which dynamic applies to your specific lanes, and budgeting accordingly, is the difference between reacting to fuel costs and planning around them.