ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has boosted the online cost of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart case. The package, which includes two 5-quart bottles, is available in several common viscosity grades. Additionally, Costco has implemented a purchase limit for certain Kirkland motor oil variants, allowing members to buy no more than two units per transaction within any seven-day period.
The new $57.99 price tag nearly doubles the approximate $30 price reported for the same quantity last year. Costco currently lists 5W-30, 5W-20, and 0W-20 Kirkland full synthetic oils at this online rate. The retailer emphasizes that prices at individual stores may differ from those shown on its website. Each case contains 10 quarts, making this price increase particularly relevant for consumers who perform routine oil changes themselves.
These purchase restrictions extend beyond Costco’s private-label offerings. Certain Mobil 1 full synthetic motor oils now have a cap of five units per membership. Mobil 1, a brand owned by ExxonMobil, is available in various formulations, including standard and high-mileage options. The affected listings on Costco include six-packs of one-quart bottles across multiple viscosity grades, broadening the scope of restrictions to another leading synthetic motor oil line.
Restrictions Cover Major Synthetic Oil Brands
Synthetic motor oils rely on highly refined base oils combined with additives to ensure engine protection under severe conditions. Group III base oils are crucial components of many synthetic lubricants sold in the United States. U.S. consumers depend heavily on imported supplies, including shipments originating from the Persian Gulf. Recent disruptions across Middle Eastern energy markets have limited the availability of certain petroleum products and lubricant inputs.
Crude oil prices have also stayed above $100 a barrel in mid-September. Brent crude traded near $107.82 on September 16, while West Texas Intermediate hovered around $104.86. Energy markets continue to reflect disruptions impacting production, exports, and key shipping routes in the Middle East. Traffic through the Strait of Hormuz remains below normal levels, and energy infrastructure in Saudi Arabia’s Red Sea region has experienced interruptions.
Rising petroleum prices and limited lubricant supplies are interconnected
The affected Kirkland products serve a wide range of passenger cars, SUVs, and light trucks. Costco states its synthetic oils offer protection against engine wear and thermal degradation. Several formulations 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 economy, engine cleanliness, and wear resistance.
Costco has not provided a detailed public explanation for the increased price of Kirkland motor oil or the implementation of purchase caps. Its online listings currently display the $57.99 price and a limit of two units per seven days on specific products. Meanwhile, separate Mobil 1 listings continue to show a five-unit per membership limit across multiple formulations. These adjustments reflect the broader context of elevated crude oil prices and tighter lubricant supplies affecting the industry.