ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online cost of its Kirkland Signature full synthetic motor oil to $57.99 per 10-quart case. This case includes two 5-quart bottles across various common viscosity grades. The retailer has also implemented purchase restrictions on certain Kirkland motor oil products. According to Costco’s current online listings, members are limited to buying no more than two units in a single transaction within a seven-day window.
The new price of $57.99 is almost double the approximately $30 price reported for the same quantity last year. Costco now lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this elevated online rate. Note that prices at warehouse locations may differ from those displayed on the company’s website. This price change primarily impacts customers purchasing larger quantities for routine vehicle maintenance, as each Kirkland package contains 10 quarts of synthetic motor oil.
Additionally, Costco has placed purchase limits on selected Mobil 1 synthetic motor oil items. As an ExxonMobil brand, Mobil 1 appears in several Costco listings with a cap of five units per membership. These include six-packs of one-quart bottles in multiple viscosity grades. Some listings cover standard formulations, while others feature high-mileage variants. Therefore, restrictions extend to both Costco’s private-label Kirkland oil and certain products from a major national lubricant manufacturer.
Motor oil purchase restrictions are not limited to Kirkland brand
Synthetic motor oil production depends on refined base oils and additives designed to safeguard engines under high heat and demanding conditions. Group III base oils are a fundamental component in many synthetic lubricants sold in the United States. A significant portion of these supplies is imported by American buyers from overseas producers, including facilities in the Persian Gulf. Recent disruptions in Middle East energy markets have led to reduced availability of some petroleum products and have tightened segments of the lubricant supply chain.
In mid-September, crude oil prices remained above $100 a barrel. On September 16, Brent crude traded near $107.82, while West Texas Intermediate hovered around $104.86. Ongoing supply disruptions in the Middle East continue to influence production, exports, and shipping routes. Traffic through the Strait of Hormuz remains below typical levels, and issues affecting Saudi Arabia’s Red Sea energy infrastructure have added further strain across petroleum markets and the broader network supplying refined products and lubricants.
Rising crude oil prices coincide with tighter lubricant availability
The affected Kirkland motor oils are suitable for many passenger vehicles, SUVs, and light trucks. Costco states that its full synthetic oils help prevent engine wear and thermal breakdown. Several products meet API SP and ILSAC GF-6A standards, which are designed for modern gasoline engines. The American Petroleum Institute oversees API motor oil standards, while ILSAC specifications focus on fuel economy, engine cleanliness, and wear protection. These standards are visible on multiple Kirkland synthetic oil listings.
Costco has yet to provide a detailed explanation for the price hike of Kirkland motor oil or the new purchase limits. Its website currently displays the $57.99 price and a two-unit, seven-day restriction for selected Kirkland products. Meanwhile, separate Mobil 1 listings still show a five-unit limit per membership on various formulations. These changes come amid a period of elevated crude prices and restricted lubricant supplies, with Costco’s posted limits defining members’ purchase quantities through affected online listings.