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. The case includes two 5-quart bottles across various common viscosity grades. Additionally, the retailer has implemented purchase restrictions on certain Kirkland motor oil products. Members are limited to buying no more than two units per transaction within a seven-day window, according to Costco’s current online listings.
This new $57.99 price tag is nearly double the approximately $30 cost reported for the same quantity last year. Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils are listed at this higher online rate. Prices at physical warehouse locations might differ from those posted online. The change particularly impacts customers purchasing larger quantities for routine vehicle maintenance, as each Kirkland package contains 10 quarts of synthetic motor oil.
Costco has also placed purchase limits on select Mobil 1 synthetic motor oil products. The ExxonMobil-owned brand 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, including both standard formulations and high-mileage variants. Consequently, the limits apply to both Costco’s private-label Kirkland motor oil and certain Mobil 1 offerings from a major national lubricant manufacturer.
Restrictions on motor oil extend beyond Kirkland brand products
Synthetic motor oils depend on refined base oils and additives engineered to safeguard engines against heat and heavy-duty use. Group III base oils are a crucial component of many synthetic lubricants sold in the United States. A significant portion of these supplies are imported from overseas producers, including facilities in the Persian Gulf. Recent disruptions in Middle East energy markets have limited the availability of certain petroleum products and tightened supply chains for lubricants.
In mid-September, crude oil prices remained above $100 a barrel. Brent crude traded around $107.82 on September 16, while West Texas Intermediate was near $104.86. Ongoing Middle East supply disruptions continue to impact production, exports, and shipping routes, with traffic through the Strait of Hormuz remaining below normal levels. Saudi Arabia’s Red Sea energy infrastructure also faced interruptions, further exerting pressure on petroleum markets and the network supplying refined products and lubricants.
Rising crude costs correlate with tightening lubricant supplies
The affected Kirkland motor oils cater to a variety of passenger cars, SUVs, and light trucks. Costco states that its full synthetic oils provide engine protection against wear and thermal stress. Several products meet API SP and ILSAC GF-6A performance 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 resistance. These standards are listed on multiple Kirkland synthetic oil products.
Costco has not issued a detailed public explanation for the recent increase in Kirkland motor oil prices or the new purchase restrictions. Currently, its website shows a $57.99 price and a two-unit limit per week for selected Kirkland items. Meanwhile, Mobil 1 listings continue to have a five-unit limit per membership on various formulations. The recent changes come amid elevated crude oil prices and tighter lubricant supplies, with Costco’s posted limits defining members’ maximum online purchase quantities for affected products.