An extra R$0.47 per liter in just one month. That is how much S-10 diesel, the standard grade sold at Brazilian gas stations, has risen since the first week of September, when it cost R$6.88, to R$7.35 last week, according to ANP, Brazil's oil and fuel regulator. It is the highest level since late April, and the bill does not stop at the pump: because diesel powers the trucks that stock Brazilian supermarkets, the increase is likely to show up in grocery prices in the coming weeks.
For a truck driver filling a 600-liter tank, the 7% increase means about R$280 more per fill-up, roughly the cost of a family's big monthly grocery run. If prices hold at this level, the extra spending tops R$3,300 per truck over a year. Prices have now risen for four straight weeks, ANP data show.
According to Folha de S.Paulo, private importers blame the pass-through on two factors: the resumption of the war in Iran and U.S. President Donald Trump's threat to halt American fuel exports. With refineries shut in the Middle East and Russia, the United States has become the main global alternative supplier and accounts for 80% of Brazil's diesel imports in October. Brazil buys about 30% of the diesel it consumes abroad; the rest comes from state-controlled Petrobras and the private refinery Acelen.
Why a war in Iran makes diesel more expensive in Brazil
Fuel prices in Brazil track import parity, meaning the cost of bringing the product from abroad, including freight and port fees. When a war drives up diesel on the international market, the increase reaches Brazilian pumps even though the country produces oil. The cost of importing diesel rose 7% over the same period, according to an estimate by consultancy StoneX and fuel importers' association Abicom: on Monday (5), import parity at the port of Paulínia, in São Paulo state, stood at R$6.70 per liter.
"[Diesel] stocks are very low all over the world. With that, supply falls and the product becomes overpriced," Abicom president Sergio Araújo told Folha.
Petrobras raised its refinery-gate diesel price two weeks ago, but by an amount matched by a new government subsidy, which cushioned the impact on consumers, Folha reported. Acelen, whose sales are concentrated in Brazil's Northeast, raised S-10 diesel by about R$0.50 per liter in September, depending on the delivery point. Federal fuel subsidies already total more than R$15 billion.
The global picture helps explain the pressure. Brent crude, the international benchmark, topped US$100 a barrel on Thursday (1st) for the first time in months, according to G1, and global oil stocks have fallen by 507 million barrels since February, according to the International Energy Agency. Although crude is flowing again through the Strait of Hormuz, exports of refined fuels such as diesel and gasoline remain below normal because the conflict also hit refineries.
On Friday (2), Brent fell back below US$100 after reports that European countries are discussing releasing 50 million barrels of diesel from emergency reserves, according to Reuters. The EIA, the U.S. government's energy agency, estimates 5.7 million barrels per day of output will remain offline in the fourth quarter and projects Middle East production returning to near pre-conflict levels only in the second quarter of 2027. Until then, Brazilian consumers are likely to live with more expensive diesel, and with its knock-on effect on the price of everything that arrives by truck.