Diesel Hits $6.51 a Gallon Nationwide, Grassley Presses Trump for Export Ban Before Midterms

Diesel prices have been climbing steadily since the U.S.-Israel war with Iran escalated in late February, when the national average sat around $3.76 a gallon. By Friday, September 18, AAA had the national average at $6.05. By Sunday, September 20, Newsweek reported the price had climbed again to $6.51, a 77% jump from $3.70 a year ago, citing calculations from Brown University's Watson Institute for International and Public Affairs.

Iowa is feeling it worse than most. AAA-Iowa put the statewide diesel average at $6.19 last week, up from just over $6 in mid-September and $5.35 a month ago, according to Newsweek and local outlet siouxcountyradio. By Sunday, Newsweek reported Iowa diesel had hit a record $6.29 a gallon. Regular gas in Iowa jumped 35 cents in a single week to $4.40, according to siouxcountyradio.

Republican Senator Chuck Grassley of Iowa wants President Trump to act. On Saturday, September 19, Grassley posted a call for the administration to "put an embargo on diesel exports like presidents in the 70s put embargoes on ag products bc food prices were inflated," a nod to the Nixon administration's 1970s restrictions on soybean and wheat exports during a domestic price spike. He first laid out the argument during his Capitol Hill Report on September 15, according to 1380kcim, warning that high diesel costs hit farmers, truckers and the broader economy.

Farmers use roughly three gallons of diesel per acre, and the average Iowa farm runs about 350 acres, according to USDA data cited by 1380kcim. That works out to an estimated $6,300 diesel bill for a typical Iowa farm this harvest season, roughly $2,600 more than a year ago. Brown University's Watson Institute estimates U.S. households have spent an additional $50 billion on diesel since the war with Iran began, based on that 77% price increase.

John Boyd, founder and president of the National Black Farmers Association, told Newsweek last week that "based on 10-dollar diesel fuel we are losing the war," adding that "struggling farmers are paying the price, losing our profit margin and going out of business." His $10 figure runs well above the $6.51 national average AAA and Newsweek have actually reported, but his underlying point about farm profit margins tracks with the USDA's own cost estimates.

Grassley isn't alone. Senate Majority Leader John Thune said Tuesday, September 15, he was "open" to looking at an export ban, and Tennessee Republican Representative Tim Burchett filed legislation this week aimed at the same problem, according to Newsweek.

The U.S. shipped nearly 400 million barrels of diesel last year, according to the Energy Information Administration. Exports hit an all-time monthly high of nearly 50 million barrels in May, as the war-driven price spike made selling fuel abroad more profitable, Newsweek reported.

Administration Says It's Already Pulled the Levers It Has

The USDA told Newsweek that Trump "recognizes that diesel powers American agriculture and this administration is not leaving any stone unturned to resolve this temporary challenge." But the administration has not committed to an export embargo.

Trump has instead called refining executives to the White House, struck an oil deal with Venezuela, eased fuel-delivery regulations, and drawn down the Strategic Petroleum Reserve to its lowest level since the early 1980s, according to CNN. Vice President JD Vance, campaigning for Iowa Republicans at a rally in Council Bluffs, declined last week to promise a timeline for relief. "I'm not going to make a promise about when it's going to return to $3," Vance told reporters, per CNN.

Dan Pickering, founder and chief investment officer at Pickering Energy Partners, told CNN that "realistically, the administration will have a tough time doing much about gasoline in the short term. They've already pulled most of the levers they can." Crude oil, not export volume, is what's setting the price, and Brent crude has climbed back above $100 a barrel as fighting with Iran resumed, according to NPR. Venezuela's oil isn't expected to meaningfully add supply for years, possibly not until 2035, CNN reported. An embargo could keep more barrels at home, but it wouldn't touch the underlying crude cost driving the spike, which is the argument the administration's own economic team appears to be leaning on by not endorsing the idea outright.

Grassley, who at 93 has represented Iowa in the Senate since 1981 and has filed to run for a ninth term in 2028, remains the loudest Republican voice pressing Trump on the issue. The Iowa Board of Regents approved plans this month to house his Senate papers at a new center bearing his name at the University of Northern Iowa, though that naming won't take effect until he leaves office.

NPR reported that Trump himself has said oil prices likely won't come down until after November's midterms. That leaves Grassley's embargo push, and every other GOP proposal on the table, competing against a war-driven global price shock that neither the White House nor Capitol Hill has shown it can quickly undo.