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 case. This case includes two 5-quart bottles available in multiple common viscosity grades. Additionally, the retailer has introduced a purchase limit on certain Kirkland motor oil items. Members are restricted to buying no more than two units per transaction within a seven-day span, according to current online listings from Costco.
The new price of $57.99 is nearly double the approximately $30 cost reported for the same quantity last year. Costco offers Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this increased online rate. It’s important to note that prices at warehouse locations might differ from those displayed on the website. This change mainly impacts customers purchasing larger quantities for routine vehicle maintenance, since each Kirkland package contains 10 quarts of synthetic motor oil.
Limits have also been placed on some Mobil 1 synthetic motor oil products at Costco. Mobil 1, a brand owned by ExxonMobil, appears in multiple listings with a cap of five units per membership. These include six-packs of one-quart bottles across various viscosity grades. Some listings feature standard formulations, while others include high-mileage variants. Consequently, the restrictions apply to both Costco’s private-label Kirkland oils and selected products from a major national lubricant manufacturer.
Restrictions on motor oil extend beyond Kirkland brand
The production of synthetic motor oils depends on refined base oils and specially formulated additives designed to safeguard engines against heat and heavy use. Group III base oils constitute 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 in the Persian Gulf. Recent disruptions in Middle East energy markets have led to reduced availability of some petroleum-based products and have tightened certain segments of the lubricant supply chain.
In mid-September, crude oil prices stayed above $100 per barrel. Brent crude traded near $107.82 on September 16, while West Texas Intermediate hovered around $104.86. Ongoing supply disruptions in the Middle East continue to impact production, exports, and shipping routes. Freight traffic through the Strait of Hormuz remains below typical levels. Additionally, Saudi Arabia’s Red Sea energy infrastructure has faced disruptions, exerting further pressure on petroleum markets and the wider network that supplies refined products and lubricants.
Rising crude oil prices coincide with tighter lubricant supplies
Many passenger cars, SUVs, and light trucks rely on the affected Kirkland synthetic oils. Costco states that its full synthetic products are designed to help protect engines from wear and thermal stress. Several products meet API SP and ILSAC GF-6A standards, which are required for modern gasoline engines. The American Petroleum Institute manages API motor oil standards, while ILSAC specifications include criteria for fuel economy, engine cleanliness, and wear protection. These standards are visible on multiple Kirkland synthetic oil listings.
Costco has not provided a detailed public explanation for the price increase or the new purchase limits on Kirkland motor oils. Presently, the website displays the $57.99 price alongside a two-unit, seven-day purchase restriction for certain Kirkland products. Meanwhile, listings for Mobil 1 still show a five-unit limit per membership on various formulations. These changes occur amid rising crude oil prices and a tightening of lubricant supplies, with Costco’s posted limits serving as the current cap on member online purchases for affected products.