Costco Starts Rationing Motor Oil. What It Means for Drivers - Newsweek

Costco has started limiting purchases of some motor oils after sharply raising the price of its Kirkland Signature synthetic product, as a shortage of a key lubricant ingredient pushes costs higher through the supply chain.

For drivers, the immediate effect is likely to be higher prices and fewer low-cost options rather than motor oil disappearing altogether. Certain synthetic products could become harder to find if the shortage persists, making it more important for motorists to check availability before an oil change and buy the specification required for their vehicle.

The membership-only warehouse club, which has long prided itself in selling products at discounted prices in bulk, has introduced the purchase limit after significantly raising the price of Kirkland Signature full synthetic motor oil, The Auto Wire first reported.

The product—a 5-quart, two-bottle case of engine oil for gasoline-powered vehicles—is used during oil changes to lubricate and protect an engine’s moving parts, helping to reduce wear, manage heat, and keep the engine running efficiently. It is now listed on Costco’s website for $57.99, up from an average in the mid-$30s which the company had maintained for years, according to the automotive-focused news media.

In the product details, Costco warns members of a "limit of one transaction per membership, with a maximum of two units every seven days." It is unclear how long the cap will remain in force.

Other motor oil product purchases are also capped, with sales of a six-quart case of Mobil 1—currently costing $44—capped at five per member.

The increase is particularly significant for drivers who buy oil in bulk and carry out their own oil changes. Costco’s former pricing made Kirkland oil a comparatively inexpensive option, while the new $57.99 price puts the 10-quart case closer to the combined cost of equivalent branded products sold elsewhere.

According to The Auto Wire, there are only two reasons why a company like Costco would cap purchases of motor oil: either they are not confident they can keep it in stock in the future, or they think the price might rise so much in the future that would make no financial sense letting customers stock-buy the product now.

Newsweek contacted Costco for comment by email on Monday and is awaiting a reply.

The disruption does not necessarily mean that drivers will be unable to obtain motor oil. Its effects may vary by brand, viscosity, specification and retailer, with some products becoming more expensive or temporarily unavailable while alternatives remain in stock.

Drivers should follow the viscosity and performance requirements in their vehicle’s owner’s manual rather than choosing an alternative solely because it is cheaper or readily available. The American Petroleum Institute provides consumer guidance explaining its engine-oil quality marks and service categories, which can help buyers identify appropriately certified products.

Motorists approaching a scheduled oil change may also want to check availability in advance, particularly if their vehicle requires a specific synthetic formulation. However, the evidence presented in this article does not establish that motorists need to stockpile oil or purchase more than they normally use.

While 10 percent to 20 percent of a synthetic motor oil like the one sold by Costco consists of chemical additives, between 80 percent and 90 percent of it is made of base oil, a product obtained by refining crude oil.

Considering the spike in oil and gas prices that has followed the start of the war in Iran in late February, oil companies are now making more profit turning crude oil into petrol, diesel or jet fuel instead of motor oil ingredients. Because of this, they are likely to produce less motor oil.

It is this supply squeeze which pushes prices up through manufacturers, distributors and retailers, until consumers see a higher price on the shelf even at a normally budget-retailer like Costco. On top of that, higher quality standards and more demanding tests for motor oil introduced in recent years have made production a costly business.

“A specific type of base oil used to make most modern engine oils, API Group III base oil, is in very short supply. The supply that is available has become extremely expensive—according to one industry source, the price of Group III has jumped 235 percent since the war in the Middle East began,” Holly Alfano, CEO of the Independent Lubricant Manufacturers Association (ILMA), told Newsweek.

“This is because about 40 percent of U.S. supply of Group III comes from the Middle East, where production facilities sustained physical damage during the war,” she added.

“Another 30 percent of supply comes from South Korea, which has relied on crude oil from the Middle East. All of this is compounded by the closure of the Strait of Hormuz, which has raised the cost of shipping and lengthened shipping timelines.”

While ILMA’s members have been working “diligently” to find alternative formulations that meet performance demands, “there is less flexibility for engine oils that are licensed under specific performance and service categories,” Alfano said.

“For example, the American Petroleum Institute has enacted emergency provisional licensing, which allows manufacturers of API-licensed engine oils to temporarily make alternative formulations that meet performance requirements.”

Oil prices were still surging on Monday, rising more than 3 percent from the previous day after a surge of around 9 percent last week following a fresh wave of attacks in the Middle East. Brent crude—the global price benchmark for roughly two-thirds to three-quarters of the world’s traded crude oil—rose above $100 a barrel last week and climbed over $108 on Monday, as Yemen’s Houthi forces launched a series of attacks on Saudi Arabia.

Costco's major competitors have not introduced purchase limits as of now.

Walmart offers equivalent-name-brand synthetic oil at roughly $32 per 5-quart jug, while a pack of two goes for nearly $64. AutoZone sells a pack of two bottles of Mobil 1 Standard Full Synthetic 5W-30 Engine Oil 5 Quart for $40.99. On Amazon, the same product goes for $31.97 for one bottle and $63.94 for two.

Newsweek contacted Walmart, AutoZone and Amazon for comment by email on Monday and is awaiting responses.

Costco’s Kirkland motor oil is a well-known low-cost alternative to premium brands, and its unusually attractive price might be a reason why the retailer has introduced limits on its purchase to prevent stockpiling and resale.

“Given the time needed to rebuild damaged Group III production facilities in the Middle East, and with the war ongoing, ILMA doesn’t expect the market to normalize until the end of next year at the earliest,” Alfano said. “Additional Group III production is being built in the U.S., but it won’t be ready until the end of next year.”

Update, 9/15/2026 4:05 a.m. ET: This article was updated to include comments from Holly Alfano.