ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online retail price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart package, which includes two 5-quart bottles and spans several common viscosity grades. The retailer also introduced a purchase cap on this item, restricting members to a maximum of two units per transaction within a seven-day window. This limitation appears on selected Kirkland Signature motor oil listings on the company’s website.
Compared to prices from roughly one year ago, the current cost represents a significant jump, as the same quantity was priced at approximately $30 during that period. Costco now offers multiple Kirkland full synthetic options online at the $57.99 mark, including 5W-30, 5W-20, and 0W-20 formulations. It’s important to note that warehouse prices may vary from online listings and differ depending on location. Each package provides 10 quarts, making this price increase particularly notable for customers purchasing oil for routine vehicle upkeep.
The purchase restrictions extend beyond Kirkland oils to include several Mobil 1 products sold via Costco. Mobil 1, a brand of ExxonMobil, is one of the most recognizable synthetic motor oil brands in the United States. Certain six-packs of one-quart bottles now have a limit of five units per membership. These restrictions affect both standard and high-mileage formulations across various viscosity grades, indicating that the limits are not exclusive to Costco’s private-label oils but also apply to a major national lubricant brand.
Limits on purchasing go beyond Kirkland motor oil
The production of synthetic motor oils relies on refined base oils and additives that meet current engine protection standards. Group III base oils are a key component of many synthetic lubricants, and the United States depends heavily on foreign suppliers for these materials. Producers located in the Persian Gulf supply a significant share of the world’s Group III output. Recent disruptions across energy markets in the Middle East have led to tighter supplies of various petroleum products and refining inputs used throughout the lubricant industry.
In addition, crude oil prices stayed above $100 a barrel in mid-September, with Brent crude trading close to $107.82 on September 16, and West Texas Intermediate near $104.86. Energy markets continue to react to disruptions affecting key Middle Eastern production and shipping routes, with traffic through the Strait of Hormuz remaining well below typical levels. Infrastructure in Saudi Arabia on the Red Sea also faced interruptions, adding pressure to regional petroleum supply chains.
Broader supply issues impact synthetic oil availability
The Kirkland oils affected by Costco include grades suitable for many passenger cars, sport utility vehicles, and light trucks, with the retailer stating these oils help prevent wear and control thermal breakdown. Certain formulations meet API SP and ILSAC GF-6A performance standards, which address engine cleanliness, fuel economy, and wear protection. Costco’s Mobil 1 listings also include a variety of standard, fuel-economy, and high-mileage options, all subject to the new purchase limits.
The company has yet to issue an official detailed explanation regarding the increased Kirkland motor oil prices or the implementation of the purchase restrictions. Currently, online listings show both the $57.99 price and the two-unit purchase limit for select products, while separate Mobil 1 pages still display a limit of five units per membership for several formulations. These changes come amid elevated crude oil prices and supply constraints in the lubricant sector, with Costco’s posted limits providing members with clear guidance on product availability and purchasing rules.