Petrol Should Drop 7 to 8 Cents a Litre on Monday and Diesel Edge Up 1 to 1.5 Cents, as the Weekly Tax Order Trims the Petrol Discount

Drivers face a split week at the pump from Monday 26 October. Petrol is expected to fall by around 7 to 8 cents a litre, while diesel is expected to rise by around 1 to 1.5 cents, according to sector forecasts reported by three Portuguese outlets. At the same time, the government has trimmed the temporary fuel-tax discount on petrol and nudged up the one on diesel.

What the forecasts say

Final prices are set by each company. ECO, citing data from the Automóvel Club de Portugal (ACP, the Portuguese automobile club), put diesel up 1 cent and petrol down 8 cents. Jornal de Negócios, citing an unnamed sector source, reported diesel up 1.5 cents and petrol down 8 cents; its updated headline, crediting the tax change, put the petrol fall at 7 cents. Notícias ao Minuto reported provisional sector estimates of petrol down 7 cents and diesel up 1 cent.

ECO also reported that, since the week of 2 to 6 March, diesel has risen by a cumulative 54.5 cents a litre and petrol by 39.6 cents, with Brent crude near 114 dollars a barrel on Friday.

The tax side: Portaria 467-A/2026/1

The government resets the ISP (imposto sobre os produtos petrolíferos, the tax on petroleum products) every Friday. This week's order is Portaria n.º 467-A/2026/1, published in the Diário da República (official gazette) on 23 October and in force from 26 October. It applies to mainland Portugal only.

• Petrol: the discount falls from 71.90 euros to 61.48 euros per 1,000 litres, and the ISP rate rises from 425.62 euros to 436.04 euros per 1,000 litres. That is about 1 cent a litre more tax before VAT.
• Diesel: the discount rises from 102.11 euros to 103.47 euros per 1,000 litres, and the rate eases from 259.49 euros to 258.13 euros.
• Pump display: the "Redução do ISP+IVA" (ISP plus VAT reduction) figure that every pump must show drops from 0.231 euros to 0.218 euros a litre for petrol and rises from 0.239 euros to 0.241 euros for diesel. We explained that figure when the display rule came in.

The order's preamble says the government adjusted the discount because it expects diesel to rise and petrol to fall next week.

Where prices stand now

The daily averages from DGEG (Direção-Geral de Energia e Geologia, the energy directorate) for Saturday 24 October were 2.174 euros a litre for simple diesel, across 1,706 stations, and 2.092 euros for simple 95 petrol, across 1,815 stations. These averages already include the discounts that stations apply. If the forecasts hold, petrol would land at roughly 2.01 to 2.02 euros and diesel at roughly 2.19 euros. That is our own arithmetic on DGEG's figures, not a price anyone has announced.

Fill up now or wait?

• Diesel: filling up today saves little. A 1 to 1.5 cent rise costs 50 to 75 cents on a 50-litre tank.
• Petrol: waiting until Monday should pay, by about 3.50 to 4 euros on 50 litres if the forecasts are right.
• The station matters more than the day. On 24 October DGEG recorded diesel prices from 1.949 euros to 2.449 euros a litre, and petrol prices from 1.929 euros to 2.335 euros. On diesel, that gap is worth 25 euros on a 50-litre fill. DGEG's Preços dos Combustíveis Online portal lets you search stations by fuel, brand, district and municipality, or view them on a map. Its cheapest stations page can be filtered by district and municipality. Station operators post their own prices there, so check the time of the last update.