Petrol and diesel increase by record monthly amounts in March

Diesel goes up by 40p in a month – 18p more than the previous record set four years ago

2 April 2026

The average prices of petrol and diesel both increased by record monthly amounts in March on the back of the conflict in Iran, analysis of RAC Fuel Watch data reveals.*

A litre of unleaded rose by 20p from 132.83p on 1 March to 152.83p by the end, surpassing the previous all-time biggest monthly jump of 16.6p seen at the end of June 2022 when petrol went up from 174.84p to 191.43p.

The increase in the average price of diesel was even more dramatic, going up 40p in March to 182.77p from 142.38p – almost doubling the previous record rise of 22p seen in March 2022 where the price went from 155.23p to 177.29p at the start of Russia’s invasion of Ukraine.

Despite the record rises seen in March, average fuel prices are still some way off the all-time highs of summer 2022 when petrol peaked at an average of 191.5p (3 July) and diesel at 199p a litre (25 June).

The sudden hikes have added £11 to the cost of filling a 55-litre petrol family car, which now stands at £84 (£84.06), and £22 for the diesel equivalent, with a full tank topping £100 (£100.52).

RAC head of policy Simon Williams said: “March has been truly unprecedented – fuel prices have never risen this fast in a single month. But while this is the biggest pence-per-litre increase ever in a month, it’s not as great in real terms as those seen during the 1973 oil crisis when the price of a barrel quadrupled.

“The increases drivers have had to endure in March 2026 far exceed those seen in the early days of the war in Ukraine.

“While the monthly rise in a litre of petrol is bad enough, the jump in the cost of diesel is even harder to swallow at 40p a litre – 18p more than the previous monthly record. With long-term RAC research showing eight-in-10 people are dependent on their vehicles, these costs must really be taking their toll on both households as well as businesses.

“Ahead of the Easter getaway, which is expected to be the busiest on the roads since 2022 with nearly 21m leisure journeys planned, we urge drivers to fill up as usual and to use the myRAC app to find the cheapest forecourts near them.”

Drivers looking to save money on their fill-ups should take advantage of the fuel finder feature in the free myRAC app. The app can be downloaded for free from the App Store or Google Play, and drivers don’t need to be RAC members to use it. Up to 10 searches a day can be made over a two, five or 10-mile radius, with each giving the five cheapest prices.

The RAC Fuel Watch web page has more information about the average price of petrol and diesel at the big four supermarkets and at motorway services. It also features graphs showing average prices since 2000 as well as a daily financial breakdown of the cost of a litre of petrol and diesel.