Fuel prices set for significant increases next week

Saturday, 5 September 2026AI summary

💶 Finance 🏖️ Daily Life #cost-of-living #fuel-prices #inflation #economic-indicator

Fuel prices set for significant increases next week — Photo: Expresso

Drivers in Portugal are facing sharp fuel price hikes starting Monday, with diesel expected to rise by up to 12 cents and petrol by 9.5 cents per litre. Despite government adjustments to the tax discount on petroleum products (Imposto sobre os Produtos Petrolíferos or ISP), prices are reaching record highs.

Update: Historic fuel price increase expected

Forecasts for the week of September 7 to 13 indicate even higher increases, with some reports suggesting diesel could rise by 15 cents and petrol by 12 cents per litre. If these projections hold, average prices may reach approximately 2.17 euros per litre for diesel and 2.14 euros for petrol, leading many drivers to seek cheaper fuel in neighboring Spain.

Context & Explainers

The ISP (Imposto sobre Produtos Petrolíferos e Energéticos) is Portugal's excise tax on petroleum and energy products, charged as a fixed amount per liter on petrol, diesel, and other fuels. It is one of the main components of fuel prices at the pump, alongside VAT and the carbon tax (Taxa de Carbono).

The government can adjust ISP rates — temporarily or permanently — to influence fuel prices. Rate cuts are a common policy tool to ease cost-of-living pressures on drivers and transport businesses, though they also reduce government revenue.

For consumers, the ISP is significant because even small changes in the per-liter rate translate into noticeable differences at the pump, particularly for diesel users and commercial transport operators.