Costco is currently limiting purchases of its Kirkland Signature full-synthetic motor oil, a popular item among shoppers, as a nationwide shortage intensifies and prices climb. Reports indicate that the retail giant has imposed a limit of two cases per membership every seven days.
This restriction is unusual for Costco, which is known for selling products in bulk quantities. A 10-quart case of Kirkland Signature full-synthetic motor oil, which includes two five-quart bottles, is now priced at $57.99 online. This represents a significant increase from the approximately $30 customers previously paid for the same product.
The motor oil shortage is closely linked to a surge in crude oil prices, which have recently approached $100 a barrel. Crude oil is the primary component in refined products such as motor oil, gasoline, and diesel fuel. When refiners can generate more revenue from producing transportation fuels, the production of lubricant base oils can become less economically attractive, leading to strained supply and increased costs for motor oil.
The broader global oil market is facing additional pressures, contributing to the increased cost of essential products like motor oil. The recent surge in crude prices is attributed to disruptions and uncertainty surrounding conflicts in the Middle East and their potential impact on vital shipping routes, including the Strait of Hormuz.
This broader economic pressure is reflected in fuel prices across the United States. As of September 14, the national average price for gasoline has risen to $4.31 per gallon, an increase of nearly one dollar since March. Diesel prices have also seen a substantial rise, with national averages reported at $6.06 per gallon, further impacting transportation and supply chain costs.
Modern synthetic motor oils, like the one Costco sells, can be particularly sensitive to supply pressures due to specific industry standards and automaker requirements for newer, high-tech engines. The Kirkland Signature 5W-30 oil meets industry standards and specific automotive manufacturer specifications, such as those for General Motors vehicles.
For some consumers, Costco's motor oil has been an affordable alternative. However, the current limitations are not entirely unexpected, as wholesale stores often reserve the right to limit quantities on purchases. Online discussions and reports indicate that customers are concerned about potential hoarding of motor oil.
Costco operates approximately 920 locations in the U.S. and has also expanded its retail presence with standalone gas stations. The company opened its first fuel-only location in Mission Viejo, California, earlier this year. These gas stations are a significant part of Costco's business, contributing substantially to its total revenue, with global fuel stations accounting for 10 percent of the company's total revenue in 2025. Costco's gas prices are typically 10 to 30 cents lower per gallon than those at other stations. The company also expanded its gas station hours nationwide in June 2025.