Fuel Prices Fall in Portugal Today as Government Quietly Trims the ISP Discount on Diesel

Drivers across Portugal are seeing cheaper fuel from this morning, Monday 20 April. Diesel (gasóleo simples) drops 11.4 cêntimos a litre to roughly €2.197/L at the pump, while gasoline 95 (gasolina simples) dips just half a cêntimo to about €1.916/L, according to weekly price data published by ECO and confirmed by Público.

The cut is the largest weekly fall for diesel in months. It would have been bigger still — about 13 cêntimos — had the government not used the same window to quietly trim the “extraordinary and temporary” tax discount that has been holding pump prices down since 2022.

What the Government Changed

By decree published in the Diário da República, the Ministry of Finance reduced the ISP (Imposto sobre Produtos Petrolíferos) discount on diesel by 1.5 cêntimos a litre. The discount on gasoline 95 was held unchanged at 4.6 cêntimos. The Government described the move as “adjusting the extraordinary and temporary discount in ISP applicable to diesel while maintaining the discount value for unleaded gasoline,” citing “a significant drop in diesel prices and a slight reduction in unleaded gasoline.”

Público noted that the rollback was published only in the official gazette, with no accompanying press release — a contrast to earlier rounds when increases in the discount were communicated to the media. The net effect for drivers: the wholesale price drop is being shared roughly two thirds with motorists and one third with the Treasury.

Why Wholesale Prices Are Falling

The pump cuts trace back to the oil market. Brent crude closed Friday at $90.38 a barrel, down about 5 per cent on the week and well off the $99 highs hit earlier in the month. Two ceasefires — one announced for Iran, one for Lebanon — have eased fears that the Strait of Hormuz, through which roughly a fifth of the world’s seaborne crude passes, could be closed for an extended period. Refining margins for diesel, which had spiked sharply on Hormuz risk, have unwound faster than for gasoline.

What This Means for Expats

For households running a car — almost everyone outside central Lisbon and Porto — the immediate saving is real but modest. Filling a 50-litre diesel tank at the new price costs about €5.70 less than it did last week. A small petrol car gains roughly 25 cêntimos a fill-up. Over a year, a typical commuter who drives 15,000 km in a diesel hatchback would save in the region of €90 if today’s prices held.

The bigger picture is less cheerful. Even after this morning’s cut, diesel in Portugal is still around 22 per cent more expensive than it was before the 2022 energy shock, and Portugal continues to carry one of the heaviest fuel-tax loads in the European Union once VAT is layered on top of the ISP. The IMF’s revised inflation forecast for Portugal — raised last week to 3.1 per cent for 2026 — cited energy as the principal driver.

The Slow Unwind of a 2022 Emergency Measure

The ISP “extraordinary discount” was introduced in March 2022 by the then PS absolute-majority government, with finance minister João Leão unveiling it as a weekly mechanism to return the additional VAT receipts collected on inflated fuel prices back to consumers via lower ISP. It was extended in successive budgets and quietly built into the architecture of pump pricing.

Today’s 1.5-cêntimo trim on diesel is the first visible step in unwinding that mechanism under the centre-right Montenegro government. The Finance Ministry has not published a roadmap for the discount’s eventual disappearance, but the budgetary logic is straightforward: with Brent retreating, every cêntimo of restored ISP brings back tens of millions of euros a year to the Treasury — revenue the government will need as it negotiates labour and energy support packages with unions and the opposition.

What to Watch Next

The ISP discount on diesel is reviewed weekly. If Brent continues to slide and the Hormuz situation stabilises, expect further trims to the discount in the coming weeks — meaning consumers will see less of any future wholesale fall reaching the pump. Conversely, if the Middle East ceasefires unravel and crude rebounds, the Government has the option of reinstating the full discount overnight.

The next weekly review lands on Sunday evening, with new prices effective Monday 27 April. ECO and DGEG will publish the figures from late Sunday afternoon.

Sources: ECO (19 April 2026), Público (17 and 18 April 2026), Diário da República.