Diesel prices are on the way to a record again in Portugal: What can change at the pump on Monday?

Another fuel increase awaits drivers in Portugal next week. While a new increase is expected in diesel and gasoline prices as of Monday, September 21, especially diesel is expected to reach historical high levels.

Although the government has made additional intervention through ISP, market forecasts indicate that the price increase cannot be prevented completely.

New historical level expectation for diesel

According to current forecasts in Portugal Resident and the Portuguese press, a significant increase in diesel prices is expected in the new week.

In the ANAREC forecast cited by Jornal de Notícias, an increase of approximately 6.5 cents per liter is foreseen for diesel and approximately 5 cents for gasoline.

Actual pump prices may vary depending on station, brand, region and trade discounts. Therefore, the national increase estimate does not mean that the price will change by the same amount at every station.

The government put the brakes on ISP

In the face of new price expectations, the government's strengthening of the support provided through the petroleum products tax ISP limits some of the increase that will be reflected at the pump.

However, current market forecasts suggest that diesel could reach a new historical high.

The government has also announced that the ISP discount will continue until the end of the year.

Why isn't just looking at the oil price enough?

The price paid at the pump in Portugal is based solely on the international crude oil price. It does not occur.

Refined product price, euro/dollar exchange rate, logistics and distribution costs, taxes and commercial policies of the stations have an impact on the final price.

For this reason, the movement in the Brent oil price and the price of gasoline or diesel in Portugal may not move exactly and simultaneously.

Price comparison increasingly important

Significant price differences can be seen for the same fuel between different municipalities and even stations in the same city.

DGEG's Combustíveis Online system allows searching the current prices reported by stations by municipality, brand and fuel type.

It becomes more meaningful to compare several stations in the immediate vicinity, especially when prices are high, before filling up.

Practical note for Monday

The new week's prices may not be reflected in the stations at the same time and in exactly the same amount.

Drivers need to look at the current price of the station they will use, not just national averages.

You can search by station on DGEG's official price portal.

Resources

Portugal Resident — 20 September 2026

https://www.portugalresident.com/diesel-prices-set-to-hit-record-high-in-portugal/

Jornal de Notícias — 19 September 2026

https://www.jn.pt/nacional/artigo/combustiveis-atingem-valores-recorde-na-proxima-semana/18128032

DGEG — Preços dos Combustíveis Online

https://precoscombustiveis.dgeg.gov.pt/

XXV Governo Constitutional — September 17, 2026

https://portugal.gov.pt/gc25/comunicacao/noticias/governo-reforca-rendimentos-e-apoios-perante-subida-dos-combustiveis