[DigitalToday reporter Jinju Hong (홍진주)] U.S. Costco has raised the price of its private-label synthetic engine oil and introduced purchase limits. Analysts say the combination of rising base oil prices, the key ingredient, and supply pressure could also increase the maintenance burden for internal combustion engine vehicles.

CleanTechnica reported on Sept. 14 (local time) that Costco raised the price of a 10-quart pack of Kirkland Signature full synthetic engine oil to $58 (about 78,000 won). It also limited purchases to 1 per transaction and capped transactions at twice a week.

Given Costco is known for its low-price policy, the move is seen as more than a simple change in sales policy and as a signal of cost pressure across the engine oil supply chain.

Rising prices for base oil, a key ingredient in synthetic engine oil, are having an impact. Amanda Hay of market research firm Independent Commodity Intelligence Services told U.S. public broadcaster NPR that base oil prices have surged to record highs since the outbreak of war, rising more than threefold.

Structural supply and demand issues in the United States are also a burden. The United States is a net exporter of major petroleum products such as gasoline, diesel and jet fuel, but it is a net importer of base oil. In particular, the raw materials used in synthetic engine oil do not have a relatively large mass-production base in the United States.

The structure in which higher base oil prices feed into final product prices is also a problem. Base oil is produced in the process of refining crude oil, like gasoline and diesel. If refiners expect higher profits from fuel production, output of lubricant feedstocks could fall, and reduced supply could ultimately push prices higher.

Rising engine oil prices have not been driven only by recent geopolitical tensions. As modern internal combustion engines become more sophisticated, demand for high-performance and premium lubricants has increased, and related cost pressures have accumulated for years. Analysts say recent tensions in the Middle East have added to that, steepening the existing upward price trend.

Higher engine oil prices could further highlight the difference between electric vehicles and internal combustion cars in terms of vehicle maintenance costs. Plug-in hybrids and extended-range electric vehicles need engine oil changes because they use internal combustion engines, but battery electric vehicles do not require engine oil replacement.

That means the gap could widen not only in fuel costs but also in regular consumables. Still, it is difficult to conclude that higher engine oil prices alone will sharply increase U.S. demand for electric vehicles. Some in the industry say online searches related to EVs have risen, while others urge caution, saying fuel cost increases alone may not significantly shift purchase demand.

Improving charging infrastructure is seen as an important variable for expanding EV adoption. Even if higher fuel and maintenance costs improve the economic case for EVs, limited access to charging could constrain the impact on consumers' purchase decisions.

Costco's influence on car sales is also in focus. Costco does not sell cars directly, but it exerts influence on new car purchases through a membership incentive program. Through Nov. 2, it is offering limited-time incentives of $1,000 to $2,000 for Volvo battery electric models EX90, EX40 and EX30, depending on membership tier and model.

The benefits can be applied alongside manufacturer incentives, and in some cases can also be combined with certain state and local government EV support programs.

Ultimately, Costco's engine oil price increase and purchase limits are an example showing that maintenance costs for internal combustion vehicles could rise broadly, beyond price changes for a specific product. If fuel and lubricant costs rise at the same time, battery electric vehicles, which do not need engine oil changes, could see their maintenance cost competitiveness stand out relatively.