ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online cost of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart pack. This bundle includes two 5-quart bottles and spans several common viscosity grades. Additionally, the retailer has imposed a purchase limit on the 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.
The new price reflects a significant jump from figures observed roughly a year ago, when the same quantity sold for around $30. Currently, Costco lists multiple Kirkland full synthetic formulations online at $57.99, including 5W-30, 5W-20, and 0W-20. It’s worth noting that warehouse pricing can differ from online rates and may vary by location. Each package contains 10 quarts, making this price hike especially relevant for customers purchasing oil for routine vehicle maintenance.
The purchase restrictions also extend to several Mobil 1 products available through Costco. Mobil 1, a brand owned by ExxonMobil, 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. This includes standard and high-mileage options across various viscosity grades, indicating that limits are not limited to Costco’s private-label products but also cover a major national lubricant brand.
Restrictions Extend 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 in many synthetic formulations. The United States depends on foreign suppliers for a significant share of these materials. Producers in the Persian Gulf supply a large portion of global Group III output. Recent disruptions in Middle East energy markets have constrained supplies of several petroleum products and refining inputs used across the lubricant sector.
Meanwhile, crude oil prices remained above $100 per barrel in mid-September. On September 16, Brent crude traded near $107.82, and West Texas Intermediate hovered around $104.86. Energy markets continue to reflect the impact of disruptions affecting key Middle East production and shipping routes. Traffic through the Strait of Hormuz is well below typical levels, and Saudi export infrastructure on the Red Sea has faced interruptions, adding further stress to regional petroleum supplies.
Broader Supply Strains Impact Synthetic Oil Markets
The affected Kirkland oils include grades suitable for many passenger cars, SUVs, and light trucks. Costco states that these oils offer protection against wear and help manage thermal breakdown. Several formulations meet API SP and ILSAC GF-6A standards, which address engine cleanliness, fuel economy, and wear protection. Mobil 1 products available through Costco also include various standard, fuel-economy, and high-mileage options.
Costco has not issued a detailed public explanation for the price increase on Kirkland motor oil or the new purchase limits. Currently, its online listings display both the $57.99 price and the two-unit limit for selected items. Meanwhile, separate Mobil 1 pages continue to show a five-unit per membership limit on multiple formulations. These adjustments come amid high crude oil prices and tightening lubricant supplies, with Costco’s posted restrictions providing members with guidance on current availability and purchasing rules.