Brent closed at 72.87 US dollars a barrel on 27 February 2026, up 2.9% on the day and at a seven month high, according to the market factbox S&P Global Commodity Insights published on 28 February 2026. Within days, tanker traffic through the Strait of Hormuz had collapsed. Mexican plants buy almost no Persian Gulf crude and almost no Persian Gulf diesel. They will pay for this anyway, through delivered fuel, freight surcharges and oil linked clauses in supplier contracts.
The decision this forces is narrow and immediate. Which cost lines in the current quarter forecast have to be repriced, by how much, and before which close.
Our reading is that the exposure sits in delivered cost rather than in the commodity price, and that the natural gas channel now getting the most attention is the weakest of the four for Mexico. Almost 72% of Mexican gas supply came from the United States by pipeline in 2024, according to the Federal Reserve Bank of Dallas in its Southwest Economy article of 31 October 2025. Seaborne LNG barely touches the Mexican balance.
What happened between 28 February and 6 March
United States and Israeli strikes on Iran began on 28 February 2026. Iran retaliated against Israeli cities and against United States bases in the United Arab Emirates, Qatar and Bahrain. Iranian state television confirmed the death of Supreme Leader Ali Khamenei. S&P Global Commodity Insights reported all of this in its factbox of 28 February 2026, alongside the price move noted above.
Two figures set the scale. Iran exported roughly 1.3 million barrels a day in January 2026, mostly to China. Goldman Sachs, cited in the same S&P Global factbox, estimated that a sustained loss of 1 million barrels a day is worth about 8 US dollars a barrel. On those numbers, Iranian export loss alone does not produce a price crisis.
The chokepoint does. The US Energy Information Administration, in its World Oil Transit Chokepoints analysis last updated on 3 March 2026, reports that 20.9 million barrels a day of crude and petroleum products moved through the Strait of Hormuz in the first half of 2025. That is about 20% of global petroleum liquids consumption and about 25% of seaborne oil trade. The same analysis puts LNG transit at 11.4 billion cubic feet a day in the first half of 2025, more than 20% of global LNG trade.
S&P Global CERA analysts wrote on 28 February 2026 that higher risk premiums, shipowner caution and delayed shipping would cut deliveries and support further price increases. That is the mechanism to watch. It prices voyages and cargo insurance before it prices barrels.
The exposure is refined product and freight, not crude
A plant does not consume Brent. It consumes diesel for standby generation and yard fleets, haulage for inbound raw material and outbound finished goods, and a long tail of oil linked consumables such as packaging resin, lubricants, solvents and industrial gases. Those prices move on product cracks and freight rates, which can travel further and faster than crude during a transit disruption.
Mexico entered this event with a lighter import position than it had a year earlier. Argus Media reported on 31 December 2025 that Pemex imported an average of 414,000 barrels a day of refined fuels between January and October 2025, down 22% from 534,000 barrels a day in the same period of 2024. Diesel imports fell further, to 83,000 barrels a day from 143,000, a drop of 42%. Those barrels arrive from the United States Gulf Coast, not from the Persian Gulf.
That distinction changes the response. A physical shortage is answered with inventory and alternate supply. A price event is answered with contract work, indexation review and hedging. On our read this is a price event for Mexico, and the companies that treat it as a stockpiling problem will tie up working capital for no protection.
Mexican diesel carries a policy buffer and it was sitting empty
The IEPS quota on diesel rose 3.8% to 7.3634 pesos a liter on 1 January 2026, and the fiscal stimulus that offsets it was set at zero for the week of 1 to 9 January. Revista TyT reported this on 31 December 2025 and noted it was the 39th consecutive week without a subsidy. The national average retail diesel price that morning was 26.400 pesos a liter.
Run the arithmetic. IEPS was roughly 28% of the pump price. Hacienda resets the stimulus weekly, so with the stimulus at zero the whole 7.3634 pesos a liter is available as a cushion if the ministry chooses to apply it. Nothing obliges it to. For a site burning 100,000 liters of diesel a month, the gap between full pass through of a world price move and full reactivation of the stimulus is about 736,000 pesos a month. That is the range a plant should carry in its forecast, not a single point estimate.
This is the part of the transmission chain that is decided in Mexico City rather than in the Gulf, and it is the part most exposure models leave out.
Where the cost lands in a Mexican plant
| Cost channel | Transmission mechanism | Likely timing |
|---|---|---|
| Diesel purchases | Spot or indexed fuel repricing, net of any IEPS stimulus | Immediate |
| Freight and logistics | Fuel surcharges, haulage resets, shipping premiums | Immediate to 30 days |
| Petrochemical inputs | Higher feedstock and transport costs | 2 to 8 weeks |
| Backup generation | Dearer diesel or fuel oil for resilience runs | Immediate |
| Working capital | Higher inventory values and precautionary buying | Immediate to quarterly |
The timing column is our judgment of how these contracts usually reset in Mexico. It is not an observed measurement, and a company with quarterly haulage resets will see the second row land later than shown.
The point of the table is that exposure is layered. A plant may buy little fuel directly and still take margin damage through freight, consumables and supplier pricing. The sites most at risk are those with high logistics intensity, thin operating margins, or contracts whose energy pass through terms nobody has read since signature. Reviewing energy procurement contracts and pass through clauses is the cheapest work available this month.
The gas channel is weaker than it looks
More than 20% of global LNG trade passes through Hormuz, on the EIA figures cited above. Mexico is not in that flow in any material way. The Federal Reserve Bank of Dallas put Mexican reliance on United States gas at almost 72% of total supply in 2024. The EIA reported on 20 October 2025 that United States pipeline exports to Mexico averaged 6.4 billion cubic feet a day in 2024, a record, and reached 7.5 billion cubic feet a day in May 2025.
Gas fueled 55% of Mexican electricity generation in 2023, again on Dallas Fed figures. So the route from Hormuz to a CFE bill runs through global gas substitution and Henry Hub sentiment, not through cargoes Mexican buyers lift. It is a slower and thinner channel than diesel. Treating it as equivalent overstates the risk and misdirects attention.
The gas risk that should worry a Mexican plant director is domestic in character. The Dallas Fed noted Mexico held less than 2.4 days of gas inventory in 2024. That is a storage and corridor problem, and we have written before about Mexico's dependence on United States pipeline gas and about how gas price moves reach industrial plants.
What could make this reading wrong
Three things would break it. If Qatari loadings stop for an extended period, European and Asian buyers will bid for United States cargoes, Henry Hub will follow, and the gas channel we have just discounted becomes the main event for Mexican power costs.
If Hacienda reactivates the diesel stimulus quickly, the pass through to Mexican pump and rack prices will be far smaller than the move in world product prices, and a plant that hedged aggressively will have paid for protection it did not need.
If transit normalizes within weeks, the freight premium unwinds before most Mexican haulage contracts reset, and the whole episode shows up as a rounding item rather than a cost event.
One limitation should be stated plainly. As of 6 March 2026 we have not seen a published diesel margin series confirming a product market move of the size the shipping behavior implies. The argument here rests on transit volumes, insurance and shipowner behavior, and on the mechanism that connects them to delivered cost. It does not yet rest on a measured margin number.
Five exposures to test this month
- Direct fuel: monthly volumes of diesel, LPG and fuel oil by site, including generator runtime.
- Freight: which inbound and outbound contracts carry automatic fuel adjustment, and on what index and reset frequency.
- Supplier pass through: the ten largest purchased items with oil linked cost structures, and the notice period each supplier must give.
- Treasury: whether operations and finance share one scenario for inventory, working capital and fuel price volatility.
- Resilience: whether onsite generation, solar or storage changes the cost of running standby plant under fuel market stress.
A plant that cannot answer these within a week is carrying more exposure than management currently assumes, because the unmeasured part of the bill is the part that reprices without a conversation.
What to do in the next 30 days
Build the facility level exposure map first, covering direct fuels, logistics, standby generation, the largest oil linked purchases and the suppliers behind them. Without it, every later step is guesswork. Then read the freight and procurement contracts for fuel adjustment mechanisms, and record the index and the reset date for each one. Those two pieces of work take days, not months, and they determine everything that follows.
Run the scenario with diesel, freight and crude separated rather than on a single oil price assumption, and stress the delivered fuel and logistics lines by 10% to 20%. Model the IEPS stimulus at zero and at full reactivation, since the difference is larger than most of the operating levers available. Finally, put finance, procurement and plant operations on the same set of assumptions before anyone starts negotiating, because fragmented responses cost more than the shock itself in most of the cases we see.
Request a diesel and freight exposure review
Mexico Energy Partners will build a facility level exposure map showing which cost lines reprice first under a stated fuel and freight scenario, and what the range looks like with and without an IEPS stimulus. To start, send twelve months of diesel and LPG purchase volumes by site, your freight and haulage contracts including any fuel adjustment clauses, generator runtime logs, and a list of the ten largest oil linked purchased items. We will confirm scope and turnaround after reviewing what you send. We do not promise a saving or a particular result.
Sources
- S&P Global Commodity Insights, "Factbox: Oil markets braced as Iran confirms death of supreme leader Khamenei", 28 February 2026.
- US Energy Information Administration, "World Oil Transit Chokepoints", analysis last updated 3 March 2026.
- Argus Media, "Viewpoint: Pemex fuel imports likely lower in 2026", 31 December 2025.
- Revista TyT, "Diesel y gasolinas inician 2026 sin estimulos y con alza al IEPS", 31 December 2025.
- Federal Reserve Bank of Dallas, Southwest Economy, "Overflowing U.S. shale gas increasingly streams to Mexico and onto global markets", 31 October 2025.
- US Energy Information Administration, Today in Energy, "U.S. natural gas exports to Mexico reach new records", 20 October 2025.