The retailer has limited purchases to two units per customer per week for its Kirkland Signature full-synthetic motor oil, which jumped from approximately $30 to $57.99 per 10-quart case. This move comes as a global lubricant shortage, linked to the ongoing Middle East conflict, pushes crude oil towards $100 a barrel. Refiners are reportedly prioritizing fuel production over lubricant stock due to strong fuel margins, further tightening base oil availability. The International Energy Agency (IEA) cut its 2026 global oil supply forecast in August, projecting a 1.8 million barrels per day deficit in Q3, more than double its prior estimate. U.S. diesel prices also crossed $6 per gallon for the first time, reaching $6.06 as of Monday.