ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online cost of its Kirkland Signature full synthetic engine oil to $57.99 for a 10-quart case. Each package includes two 5-quart bottles across several popular viscosity grades. Additionally, the retailer has introduced purchase restrictions on select Kirkland motor oil products. Customers are limited to buying no more than two units per transaction within a seven-day period, according to current online listings from Costco.
The updated price of $57.99 is nearly double the approximately $30 that was reported for the same quantity last year. The retailer lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this increased online rate. Prices at physical warehouse locations may differ from those displayed online. This change impacts consumers purchasing larger quantities for routine vehicle maintenance, as each Kirkland package provides 10 quarts of synthetic motor oil.
Costco has also set purchase limits on certain Mobil 1 synthetic motor oil products. Mobil 1, a brand owned by ExxonMobil, is featured in several Costco listings with a cap of five units per membership. These restrictions include six-packs of one-quart bottles in various viscosity grades. Some listings involve standard formulations, while others are high-mileage variants. Consequently, the restrictions apply not only to Costco’s private-label Kirkland motor oil but also to select products from a major national lubricant brand.
Restrictions on motor oils extend beyond Kirkland offerings
Synthetic motor oil production depends on refined base oils and specially formulated additives designed to protect engines under heat and heavy use. Group III base oils are a key element in many synthetic lubricants sold in the United States. A significant portion of these supplies is imported by American buyers from overseas producers, including facilities located in the Persian Gulf. Recent disruptions in Middle East energy markets have led to reduced availability of some petroleum products and tighter supplies in parts of the lubricant supply chain.
As of mid-September, crude oil prices stayed above $100 per barrel. On September 16, Brent crude was trading around $107.82, while West Texas Intermediate was near $104.86. Ongoing disruptions in Middle Eastern supply chains continued to impact production, exports, and shipping routes. The Strait of Hormuz saw traffic below typical levels, while Saudi Arabia’s Red Sea energy infrastructure faced interruptions, adding further pressure to petroleum markets and the broader network that supplies refined products and lubricants.
Climbing crude oil prices tighten lubricant availability
Many passenger cars, SUVs, and light trucks rely on the affected Kirkland motor oils. Costco states that its full synthetic products are designed to safeguard engines against wear and thermal degradation. Several of these formulations meet API SP and ILSAC GF-6A performance standards for modern gasoline engines. The American Petroleum Institute oversees API motor oil standards, while ILSAC specifications address factors like fuel economy, engine cleanliness, and wear protection. Several Kirkland synthetic oil listings display these standards.
Costco has not publicly provided detailed reasons for the recent price hike of Kirkland motor oil or the new purchase restrictions. The company’s website currently lists the $57.99 price and a two-unit seven-day limit on select Kirkland products. Meanwhile, listings for Mobil 1 continue to show a five-unit purchase cap per membership across multiple formulations. These adjustments coincide with heightened crude oil prices and limited lubricant supplies, with the posted purchase limits now dictating how much members can buy online from affected listings.