The U.S. fuel crisis has now reached beyond the gas pump, with Costco capping motor oil purchases and nearly doubling its price. The bulk-buying retailer is restricting Kirkland Signature full-synthetic motor oil to two units per membership every seven days, and the cost has risen from roughly $30 to $58 per 5-quart two-pack.
A shift this remarkable would not be expected from an enterprise whose entire reputation depends on steep savings tied to bulk orders. Yet the disruptions that prompted it are genuine, and they are intensifying.
The Strait of Hormuz Is Closed
The root cause is the closure of the Strait of Hormuz, the narrow waterway through which roughly a fifth of the world’s oil passes. Attacks on Middle Eastern energy infrastructure have followed, including a damaging March 2026 airstrike on Qatar’s Pearl GTL facility and last week’s drone attack on Saudi Arabia’s critical East-West pipeline.
More than 500 million barrels have left global oil supplies since the fighting started in February. Chevron’s chief executive, Mike Wirth, described the extent of it during a Friday appearance at an industry gathering, saying “we don’t have nearly the buffers in the system that we did when it began.”
Brent Crude Surges Past $109
The figures paint a clear picture. On Monday, Brent crude (CBX26) moved past $109 per barrel, having traded below $72 as recently as early July. U.S. diesel reached an all-time high of $6.23 per gallon, while gasoline rose to $4.31. The IEA has revised its forecast for a third-quarter global supply gap, now estimating a shortfall of 1.8 million barrels per day, more than twice what it had previously projected.
Earlier today, WTI crude futures (CLV26) reached a new four-month peak of $106.75 per barrel.
Why Motor Oil Prices Are Moving
The crude barrel’s lowest rung belongs to motor oil. Base oil, which comprises 80% to 90% of a finished product, shares the same barrel with gasoline and diesel. Since crack spreads on transportation fuels sit roughly a dollar per gallon above year-ago levels, refiners naturally put fuel production ahead of lubricant feedstock.
The result is a reduced supply of base oil for motor oil. More than 40% of the Group III base oils used by the United States come from the Middle East, and CEO Holly Alfano of the Independent Lubricant Manufacturers Association told “Newsweek” that prices for these oils have risen sharply 235% since the war started. Damage to production facilities, tight supplies from South Korea, and longer shipping times are all adding to the strain on the market.
GM’s Dexos1 Gen 3 certification and seven additional API SP laboratory tests now apply to modern synthetic oils, adding layers of licensing and testing cost that cannot simply be reformulated away.
Costco’s Move Discourages Hoarding
The design of Costco’s cap appears built to discourage stockpiling, especially with supply chain doubts still hanging over the business. Higher energy costs have hit customers directly, and the limits look like an attempt to manage demand during a time of great uncertainty.
Administration officials, including Energy Secretary Chris Wright, have dismissed the disruption to key oil infrastructure in Saudi Arabia as a “temporary” disruption to oil prices. But the data tells a different story.
Inflation Is Already Above Target
In August, annual CPI inflation rose to 3.4%, far exceeding the Fed’s 2% target. Meanwhile, ten-year Treasury yields ($TNX) have risen above 5% for the first time since 2007.
| Measure | August Reading |
|---|---|
| CPI inflation | 3.4% |
| 10-year Treasury yields | Breached 5% |
The Fed’s Rate Tool Faces a Mismatch
Wednesday’s anticipated move by the Federal Reserve will bring its benchmark rate up by 25 basis points, settling into a range of 3.75% to 4.0%. The CME FedWatch tool assigns a 94.5% probability to a hike. Still, the instrument being used does not suit the issue facing global energy markets.
Higher prices come from a physical supply shortage, not from too much demand that raising interest rates could meaningfully control. Higher borrowing costs cannot reopen the Strait of Hormuz, fix a broken Saudi pipeline, or bring back destroyed base-oil production capacity in the Persian Gulf. They cannot either change how refineries direct their output from high-margin diesel toward lower-margin lubricant base stocks.
A rate increase might gently cool total demand and steady public expectations for price growth, yet it carries a heavy expense: mortgage costs sit well past 7%, credit card APRs rest above 22%, and the economy faces mounting strain while expanding close to its capacity at roughly 2% real GDP.
Moody’s Warns of a Policy Mistake
Moody’s economist Mark Zandi warned that “The odds of a serious Fed policy mistake are uncomfortably high and rising,” noting that aggressive tightening in the face of supply-driven inflation risks triggering layoffs and a “self-reinforcing negative cycle” without addressing the underlying cause of rising prices.
The Market May Not Recover Soon
American consumers may keep running into motor oil purchase limits, record diesel prices, and rising household energy costs for months to come. The Group III base oil market is not expected to return to normal until the end of next year, by which point new domestic production capacity is scheduled to begin operating.
The Brown University tracker has already estimated that the bill to families since February exceeds $816, and it rises by roughly $1 million every two minutes.
What This Means for Shoppers
A bulk retailer that built its reputation on cheap, plentiful goods has started rationing a basic item and nearly doubling its price. That kind of change is not a typical seasonal adjustment; it is a structural shift driven by a war in the Middle East.
Wednesday’s rate increase from the Fed might help lock in stable inflation expectations, yet it cannot resolve the supply issue. The cushion of oil has vanished, and the pipelines keep being targeted. The expense continues to mount.
Consumers should get used to limits and prices that don’t fall fast. The lesson is straightforward: anticipate more of this. The Strait of Hormuz is shut, and the world’s refineries are working with a smaller barrel.
The warehouse club chain Costco has begun rationing motor oil, and other retailers across the country could soon face the same pressure to limit purchases.
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