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 contains two 5-quart bottles and spans multiple common viscosity grades. The retailer has also imposed a purchase cap on this product, allowing members to buy no more than two units per transaction within a seven-day window. This restriction appears on select Kirkland Signature motor oil listings on the company’s website.
Compared to roughly a year ago, this new price reflects a significant jump from the previous cost of about $30 for the same quantity. Currently, Costco lists various Kirkland full synthetic formulations online at $57.99, including 5W-30, 5W-20, and 0W-20. It should be noted that warehouse prices might differ from online rates and can vary depending on location. Each package offers 10 quarts, making the price increase particularly noticeable for customers purchasing oil for routine vehicle upkeep.
The purchase restrictions are also applied to several Mobil 1 products available through Costco. As an ExxonMobil brand, Mobil 1 is among the most recognized synthetic motor oil labels in the United States. Now, selected six-packs of one-quart bottles are limited to five units per membership. These listings include both standard and high-mileage formulas across multiple viscosity grades, meaning the restrictions extend beyond Costco’s private-label oil and involve a major national lubricant brand.
Limitations Extend Beyond Kirkland Synthetic Oil
The production of synthetic motor oils relies heavily on refined base oils and additives that meet current engine protection standards. Group III base oils are a significant component in many synthetic formulations. The United States depends on international suppliers for a large portion of these essential materials. A considerable share of global Group III output is supplied by producers in the Persian Gulf. Recent disruptions in Middle East energy markets have limited supplies of various petroleum products and refining inputs used throughout the lubricant industry.
Meanwhile, crude oil prices remained above $100 a barrel in mid-September. As of September 16, Brent crude was trading near $107.82, while West Texas Intermediate hovered around $104.86. Energy markets continued to react to disruptions affecting major Middle Eastern production and shipping routes. Traffic through the Strait of Hormuz stayed well below normal levels, and Saudi Arabian export infrastructure on the Red Sea faced interruptions, adding further pressure to regional petroleum supplies.
Broader Supply Challenges Impact Synthetic Oil Market
Costco’s affected Kirkland products include various grades used in many passenger cars, sport utility vehicles, and light trucks. The retailer states that these oils help prevent wear and control thermal breakdown. Several formulations meet API SP and ILSAC GF-6A performance standards, which address engine cleanliness, fuel economy, and wear protection. Additionally, Mobil 1 listings at Costco include multiple options, such as standard, fuel-economy, and high-mileage formulations.
Costco has yet to provide an official detailed explanation for the increased price of Kirkland motor oil or the new purchase limits. Currently, its online listings display both the $57.99 price and the two-unit restriction for certain products. Meanwhile, separate Mobil 1 pages still show a five-unit limit per membership on several formulations. These updates come during a period characterized by elevated crude prices and tighter lubricant supplies, with Costco’s posted restrictions offering members clear guidance regarding current availability and purchasing rules.