Costco has started rationing motor oil and nearly doubled the price of its Kirkland Signature brand, responding to upheaval in global oil markets due to ongoing conflict in Iran. The cost of a two-pack of five-quart Kirkland Signature full-synthetic motor oil has surged to about $58, from approximately $30 last year, as reported by the Associated Press. Moreover, the retailer has set a limit of two packs per customer each week while also placing restrictions on certain Mobil 1 motor oil items.
Attorney Antonio Moore mentioned on social media that this situation was anticipated following the blockade of the Strait of Hormuz that has been largely in effect since the start of the Iran conflict in February. This chokepoint is crucial for oil transport, and Moore’s comments highlight the ripple effects of such restrictions once they hit the news.
Costco’s website now indicates that members can only make one transaction per week for certain types of Kirkland Signature full-synthetic motor oil, allowing a maximum of two units every seven days. Moore also pointed out that growing consumer demand, combined with the actual shortage, is leading to these purchasing limits and encouraged people to ensure they have enough oil for their vehicles.
As crude oil prices continue to rise, with Brent crude exceeding $109 a barrel, the situation worsens, primarily due to the ongoing war in Iran limiting oil supply and a significant Saudi pipeline that remains mostly out of operation after an attack. The production of motor oil is directly tied to the crude oil refining process, which is also tasked with producing gasoline and diesel, exemplifying the complex interdependencies within the oil market.
The Energy Information Administration suggests that from a typical 42-gallon barrel of crude, roughly 20 gallons turn into gasoline while less than half a gallon becomes lubricants like the motor oil consumers are now scrambling for. A request for comment from Costco was not immediately returned.
Oil Services Are Feeling The Squeeze
Costco isn’t the only retail company grappling with the consequences of the global oil shortage.
A spokesperson from Jiffy Lube remarked that the closure of the Strait of Hormuz is causing challenges in pricing and availability. Jiffy Lube operates over 2,000 service centers in the U.S. and mentioned they sometimes face temporary shortages of particular products due to these supply constraints.
Since these centers are individually owned and operated, franchisees establish their pricing based on local conditions. It’s notable that even before this recent spike in oil prices, rates for oil changes were already escalating at a rate faster than general inflation, with prices among major providers increasing by 6.2% from July 2025 to July 2026, according to automotive consulting data.
The U.S. relies heavily on imports from the Persian Gulf for certain base oils essential for synthetic motor oil production, making supply disruptions through the Strait a significant concern.
Costco is now rationing motor oil
“stores are now imposing a two-per-customer, per-week limit.” – Drive pic.twitter.com/sruyQK6axS
— Don Johnson (@DonMiami3) September 13, 2026
The Oil Crunch Doesn’t Stop At Your Car
The ramifications of tightening oil supplies extend beyond just consumer motor oil purchases. Diesel prices jumped to $6.06 per gallon nationally on Friday, significantly up from $3.71 just a year prior. This price surge affects various sectors, like transportation, construction, and agriculture, which largely rely on diesel fuel, and ultimately impact consumer goods.
The trucking industry, for instance, is particularly vulnerable, given that trucks were responsible for moving over 11 billion tons of freight in 2024. As a result, increased diesel costs can trickle down to consumer prices at grocery stores, as farmers use it for agricultural operations and transportation of goods to distribution centers.
The pressure on these supply chains is intensifying, especially with multiple crucial oil routes experiencing disruptions. The situation at the Strait of Hormuz is still quite precarious, and a major pipeline in Saudi Arabia has been shut down following an attack, further complicating the flow of oil.
Moreover, the cost of transporting crude oil is skyrocketing. For example, earnings for supertankers shipping from the Middle East to China have hit record highs, and the price for shipping crude from the U.S. Gulf Coast to China has also reached staggering levels.
