US base oils and lube output fell in July to a three-month low because of a slump in production in the US West coast region.

Base oils and lube output of 5.10mn bl (718,450t) in July edged down from 5.22mn bl the previous month, according to the EIA.

Production fell by 9pc from 5.62mn bl during the same month a year earlier.

The drop in output for a fourth straight month left total supplies of 35.10mn bl in the first seven months of the year up just 0.6pc from year-earlier levels.

The lower production for several months to July coincided with and remained sufficient to cover firm domestic and overseas demand during that period.

The firm supply-demand fundamentals supported US base oils prices at elevated levels compared with prices in markets like Asia-Pacific.

Base oils production fell in July because of plant maintenance work in the US West coast region.

Paraffinic base oils output of 26,000bl in the region in July fell from 167,000bl the previous month to the lowest since late-2016.

Output in the US West coast had averaged more than 430,000 bl/month in 2021. Production levels remained well below that level in the past five months to July.

The trend cut the region’s total output to 1.85mn bl in the first seven months of the year. The volume was down almost 40pc from 3.06mn bl during the same period last year.

Upcoming plant maintenance work in the US is likely to cap any recovery in the country’s base oils output over the coming months.

But overseas demand weakened during the third quarter compared with the first half of the year in the face of slowing lube consumption and rising arbitrage supplies from other markets.

The weaker fundamentals have already prompted a drop in US base oil prices.