ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart case. Each case includes two 5-quart bottles available in various common viscosity grades. The retailer has also introduced purchase restrictions on certain Kirkland motor oil items. 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 online price of $57.99 is almost double the approximate $30 price reported for the same quantity last year. Costco lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this elevated rate. Prices at physical warehouse stores might differ from those displayed online. This change primarily impacts customers purchasing larger quantities for routine vehicle maintenance, as each Kirkland package holds 10 quarts of synthetic motor oil.
Additionally, Costco has set purchase limits on certain Mobil 1 synthetic motor oils. Mobil 1, a brand owned by ExxonMobil, appears in several Costco listings with a cap of five units per membership. These restrictions apply to six-packs of one-quart bottles in various viscosity grades. Some listings feature standard formulations, while others include high-mileage variants. Consequently, the limits affect both Costco’s private-label Kirkland motor oils and select products from a prominent national lubricant brand.
Restrictions on motor oil extend beyond Kirkland offerings
Synthetic motor oil production depends on refined base oils and additives engineered to shield engines under high heat and strenuous conditions. Group III base oils are a key component in many synthetic lubricants sold in the United States. A significant portion of these supplies is imported from overseas producers, including facilities in the Persian Gulf. Recent disruptions across Middle East energy markets have limited the availability of some petroleum products and tightened parts of the lubricant supply chain.
Crude oil prices remained above $100 per barrel in mid-September. On September 16, Brent crude traded near $107.82, while West Texas Intermediate was close to $104.86. Ongoing Middle East supply disruptions continued to influence production, exports, and shipping routes. Traffic through the Strait of Hormuz stayed below normal levels. Interruptions also impacted Saudi Arabia’s Red Sea energy infrastructure, increasing pressures across petroleum markets and the network that supplies refined products and lubricants.
Rising crude oil prices coincide with tighter lubricant availability
The affected Kirkland motor oils serve many passenger cars, sport utility vehicles, and light trucks. Costco states that its full synthetic oils help safeguard engines from wear and thermal degradation. Some products meet API SP and ILSAC GF-6A standards, which are designed for modern gasoline engines. The American Petroleum Institute manages API motor oil standards, while ILSAC specifications focus on fuel efficiency, engine cleanliness, and wear protection. These standards are present on several Kirkland synthetic oil listings.
Costco has not provided a detailed public explanation for the price hike of Kirkland motor oils or the new purchase limits. Its website now displays the $57.99 price and a two-unit seven-day restriction on selected Kirkland products. Meanwhile, separate Mobil 1 listings still show a five-unit limit per membership on various formulations. These changes come amid elevated crude oil prices and a constrained lubricant supply, with Costco’s current limits defining how much members can buy through affected online listings.