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 package includes two 5-quart bottles and is available in multiple common viscosity grades. The retailer now enforces a limit of one transaction per member and a maximum of two units within seven days. These restrictions are clearly displayed on the product pages for selected Kirkland Signature synthetic motor oils.
This $57.99 price marks a significant rise from the approximately $30 reported for the same amount last year. Currently, Costco lists its 5W-30, 5W-20, and 0W-20 full synthetic two-packs at $57.99 online. The company notes that warehouse prices can vary depending on location. Each package offers 10 quarts of motor oil, making the price increase notable for members who perform their own vehicle maintenance.
In addition, Costco has imposed purchase limits on various Mobil 1 full synthetic motor oil products. Presently, listings show a restriction of five units per membership for certain six-packs that contain one-quart bottles. These include multiple viscosity options and high-mileage formulations. The restrictions extend beyond Kirkland Signature products, encompassing other popular synthetic motor oils available through the warehouse retailer.
Purchase restrictions now cover multiple synthetic motor oil brands
Synthetic motor oils combine highly refined base oils with additives designed to safeguard engines and prevent deposits, wear, and thermal degradation. Group III base oils are a critical component in the supply chain of many synthetic lubricants. The United States sources a significant portion of these materials from producers around the Persian Gulf. Recent disruptions affecting energy production and shipping in the Middle East have led to tighter availability of certain petroleum products and refining inputs.
Meanwhile, crude oil prices remain elevated as of mid-September. Brent crude was trading near $107.82 a barrel on September 16, while West Texas Intermediate hovered around $104.86. Both benchmarks have stayed above $100 after weeks of disruptions impacting major energy routes in the Middle East. Shipping through the Strait of Hormuz has sharply declined from usual levels, and regional energy infrastructure, including Saudi Arabia’s Red Sea export facilities, has experienced disruptions.
Rising crude oil costs intensify pressure on energy markets
The affected Kirkland Signature products include popular grades used across a broad spectrum of passenger vehicles. Costco states that its synthetic motor oils offer engine wear protection and help prevent thermal breakdown. Several formulations also meet API SP and ILSAC GF-6A performance standards. The Mobil 1 products listed by Costco include standard, fuel-economy, and high-mileage options, with purchase restrictions clearly shown on multiple product pages.
Costco has not issued a detailed public explanation for the increase in motor oil prices and the imposition of purchase limits. However, its online listings now explicitly display both the $57.99 price for Kirkland Signature oil and the two-unit limit per week. Meanwhile, Mobil 1 listings still show a five-unit cap per membership. These changes coincide with rising petroleum costs and limited lubricant supplies, situating Costco’s pricing and restrictions within a broader context of tight energy markets.