ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart case. Each case includes two 5-quart bottles available in several common viscosity grades. The retailer has also introduced a purchase limit on certain Kirkland motor oil products. According to Costco’s current online listings, members can buy no more than two units in a single transaction within a seven-day window.
The new price of $57.99 is nearly double the approximately $30 cost reported for the same quantity last year. Costco lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this elevated online price. Actual prices at warehouse stores may vary from those shown online. This change mainly impacts customers purchasing larger quantities for routine vehicle maintenance, as each Kirkland package contains 10 quarts of synthetic oil.
Additionally, Costco has imposed limits on some Mobil 1 synthetic motor oils. Mobil 1, a brand owned by ExxonMobil, appears in multiple Costco listings with a cap of five units per membership. These include six-packs of one-quart bottles in various viscosity grades. Some listings feature standard formulations, while others include high-mileage options. The restrictions thus apply to both Costco’s private-label Kirkland motor oil and select products from a major national lubricant brand.
Restrictions on motor oil extend beyond Kirkland products
Synthetic motor oil depends on refined base oils and additives that protect engines under heat and heavy use. Group III base oils are a key ingredient in many synthetic lubricants sold in the United States. Many of these supplies are imported from overseas producers, including facilities in the Persian Gulf. Recently, disruptions in Middle East energy markets have reduced the availability of some petroleum products and caused supply chain tightening for lubricants.
Crude oil prices stayed above $100 a barrel in mid-September. Brent crude traded around $107.82 on September 16, while West Texas Intermediate hovered near $104.86. Ongoing Middle East supply issues affected production, exports, and shipping routes. Traffic through the Strait of Hormuz remained below normal. Disruptions also impacted Saudi Arabia’s Red Sea energy infrastructure, adding pressure to petroleum markets and the broader supply chain for refined products and lubricants.
Rising crude oil prices coincide with limited lubricant supplies
The Kirkland motor oils affected serve many passenger cars, SUVs, and light trucks. Costco states that its full synthetic oils help protect engines from wear and thermal breakdown. Some products meet API SP and ILSAC GF-6A standards for modern gasoline engines. The API sets motor oil standards, and ILSAC covers fuel economy, engine cleanliness, and wear protection. Several Kirkland synthetic oils display these standards in their listings.
Costco has not provided a detailed explanation for the price hike or the new purchase restrictions on Kirkland motor oils. Its website currently displays the $57.99 price and a two-unit seven-day limit on certain products. Meanwhile, Mobil 1 listings still show a five-unit limit per membership on various formulations. These changes occur amid rising crude prices and tighter lubricant supplies, with Costco’s posted limits now defining how much members can buy online from affected listings.