WASHINGTON: US President Donald Trump says he has ordered the Department of Justice (DoJ) to look into petrol prices, complaining that they aren’t falling fast enough.

“The big oil companies are not dropping their price at the pump commensurate with the sharply lower prices they are paying for oil,” he said in a post on Truth Social.

“Petrol prices better start going down a lot faster than what I’m seeing!”

Trump did not elaborate on the instructions given to the DoJ.

Average nationwide petrol prices surged to the highest level since 2022 following strikes by the United States and Israel on Iran, which resulted in the closure of the Strait of Hormuz – a key waterway for about a fifth of seaborne crude.

They have declined less quickly than crude oil – which accounts for half the price of petrol – after Washington and Tehran signed an interim peace deal that saw traffic through the waterway pick up.

US retail petrol prices remain above the five-year seasonal average, standing at US$3.93 as of Wednesday, according to data from the American Automobile Association.

Trump said he thinks prices should be at US$2.25 by now, citing the “gusher” of crude coming out of the Persian Gulf now that ship traffic through the strait is increasing.

Large oil companies are to blame, he said, for the fact that pump prices aren’t lower. 

“It’s Exxon Mobil. It’s Chevron. It’s Shell. It’s BP – it’s a lot of them,” the president said.

“The oil companies are possibly gouging. I hope they’re not. Otherwise they’re going to be in big trouble.”

Part of the reason pump prices haven’t fallen faster stems from summertime demand and fuel requirements.

“It has to do with the seasonality of petrol prices which tend to be higher in the summer, and in general, there tends to be a lag of about 10 days or so between wholesale prices on Wall Street and retail prices at the pump,” Daan Struyven, co-head of global commodities research and head of oil research at Goldman Sachs, said on Wednesday on Bloomberg Television.

“Structurally, we think refined product markets are tighter than crude markets.”

High petrol prices have become a political vulnerability for the Republican Party ahead of US midterm elections in November.

Democrats eager to highlight cost-of-living issues have been making pump prices a key point of attack.

The supply situation for both crude and petrol has improved, but stockpiles remain depleted.

US commercial inventories of petrol held by oil refiners, trading firms and wholesalers which supply filling stations are currently around the lowest levels for the time of year since 2014, according to US government data. 

Historically, economists and energy experts said, it’s often taken longer for oil and petrol prices to fall after a run-up in costs, especially when provoked by a physical disruption – even as those constraints abate. 

“Our industry shares the goal of delivering relief at the pump and restoring stability to global energy markets,” Bethany Williams, a spokesperson for the American Petroleum Institute, said by email.

“Petrol prices don’t move in lockstep with crude oil, especially during a major global disruption that is still affecting supply, refining and inventories.” — Bloomberg