U.S. refining capacity fell by 263,000 barrels per day (bpd), or 1.43%, in 2025, driven by the planned conversion of a major Houston refinery and a Los Angeles-area plant that shuttered citing market dynamics in California, a state known for strict environmental regulations.
Marathon Petroleum, based in Findlay, Ohio, continues as the largest refiner with 2.986 million bpd, or 16.4% of national capacity, according to a report released by the U.S. Energy Information Administration (EIA) on Friday.
San Antonio-based Valero Energy Corp is the second largest at 2.23 million bpd, or 12% of U.S. capacity. Saudi Aramco-owned Motiva Enterprises’ Port Arthur, Texas refinery continues as the nation’s largest single refinery with a capacity of 656,400 bpd, according to the report. The refinery increased in capacity by 15,900 bpd through improving refining efficiency.
The report is based on reports on capacities of individual refineries filed by the companies to the EIA by January 1, 2026.
It is not unusual for refinery capacity to dip from year to year, with eventual recovery as refineries expand capacity by improving operating efficiency.
In February 2025, chemical maker Lyondell Basell Industries shut its 263,776 bpd Houston refinery to convert the site to a petrochemical plant. The company had said the refinery no longer fit its business model as global chemical producer.
In October 2025, Phillips 66 shut its 138,700 bpd Los Angeles-area refinery saying the plant’s viability was uncertain due to changing market dynamics in California.
(Reporting by Erwin Seba; Editing by Nathan Crooks and David Gregorio)