Petrol Is Up Nearly 11p in a Month and Duty Rises on 1 September: The UK Fuel Market in August 2026

June was a remarkable month at the pumps. Prices fell at a pace rarely seen in UK fuel retailing, and drivers who filled up in the first week of July paid less than at any point since the spring.

That window has closed, and it has closed hard. Over the past fortnight the price of petrol rose at almost every forecourt in the country. Not most of them. Almost all of them.

What Prices Are Doing Right Now

The figures below come from Fuel Finder's database on 3 August 2026, covering every forecourt in the government price feed that has reported within the last 14 days. That is 7,757 stations out of 8,064 active sites.

A 55-litre fill of petrol now costs around £88.50. The same tank of diesel costs about £99.25, which is nearly £9 more than it would have been a month ago.

One note on method, because it changes how these numbers compare with others you will see quoted. This is an unweighted average: every forecourt counts once, from a Highland single-pump site to a Tesco Extra. Figures published by motoring organisations are typically weighted by sales volume, which pulls the average down because supermarkets sell a disproportionate share of the country's fuel from a small number of very busy sites. Both are valid. They answer different questions, and the unweighted figure is the more useful one when you are deciding where to stop.

The Reversal, in Numbers

Comparing today's national average against a historic one can mislead, because the set of reporting stations changes from day to day. The table below avoids that. It takes the stations reporting fresh prices today and compares each one against its own price at earlier dates. Same forecourts, like for like.

Two things stand out.

First, the move is broad and one-directional. Of 7,094 forecourts with a comparable price from a fortnight ago, 6,975 had raised petrol, 90 had left it unchanged, and 29 had cut it. Price rises that uniform are a wholesale story rather than a retailer story. When costs move this sharply, every operator follows within days.

Second, the rally has now gone further than a simple recovery. A week ago it was still possible to describe July as clawing back June's fall. That is no longer true for petrol, which is 3.8p above where it stood three months ago. Diesel remains 7.7p below its early-May level, but that cushion is shrinking quickly. At 60 days the gap is down to 1.4p.

Why It Happened: Crude Oil

Brent crude, taken from the daily closes Fuel Finder records from the US Energy Information Administration, explains the move:

• 18 May 2026: $116.73 a barrel, the peak of the spring spike
• 2 July 2026: $68.53, the lowest close in the tracked series
• 23 July 2026: $105.32, a rise of 54% in three weeks
• 27 July 2026: $91.82, the most recent confirmed close

Sterling offered no shelter. In pounds, Brent went from £51.50 a barrel on 2 July to £78.88 on 23 July.

The spring spike and its unwinding were driven by geopolitical risk in the Gulf and the market's subsequent repricing of that risk. Reporting on the precise causes of the July rebound varies considerably in quality, so this article does not attribute it to a single event. What is not in doubt is the direction and scale of the move, and that UK pump prices followed it on the expected lag.

There is one piece of better news in that list. Crude has fallen back roughly 13% from its 23 July peak, while pump prices are still climbing. Retail is lagging wholesale, as it always does. If crude holds near current levels, the rate of increase at the pump should slow within a week or two. That is a conditional statement rather than a forecast, and the same crude market has moved 50% in three weeks twice this year.

A note on timing: the EIA publishes with a delay, so 27 July is the most recent confirmed close available rather than today's price.

Fuel Duty Rises in Four Weeks

The second force shaping the months ahead is tax, and it is already legislated.

Fuel duty has stood at 52.95p per litre since the temporary 5p cut was introduced in March 2022. The Autumn Budget 2025 confirmed that cut will be withdrawn in stages:

The pump effect is larger than the duty change because VAT is charged on top of duty. A 1p duty rise becomes roughly 1.2p once 20% VAT is applied.

In cash terms, the September increase adds about 66p to a 55-litre fill. By March 2027, with the full 5p restored, that same tank costs around £3.30 more than today on duty alone.

It is worth seeing how much of the current price is already tax. At 160.9p for petrol, duty is 52.95p and VAT is 26.8p. Together that is just under half the pump price, before the retailer, refiner or oil producer takes anything.

There is a fuller breakdown of the phased increases in the guide to the September 2026 duty rise.

Where You Fill Up Beats When

Timing gets the attention, but the spread across forecourts is far larger than any week-to-week movement. On 3 August the cheapest petrol in the UK was 139.9p and the dearest 198.0p. That is a range of 58p per litre, or nearly £32 on a single tank.

By brand

Grouped, the big supermarkets plus Costco average 158.8p for petrol against 161.5p everywhere else, a gap of 2.6p. For diesel the gap is wider at 4.2p (177.1p against 181.3p).

That supermarket advantage has narrowed over the past week, which is what usually happens in a fast-rising market. The chains that reprice most often move first, and the rest of the market closes the gap as it catches up.

By region

Averaging petrol by postcode area across forecourts reporting fresh prices, Northern Ireland remains comfortably the cheapest part of the UK at 154.0p across 460 sites. At the other end sit the Highlands (IV) at 164.6p, Chelmsford (CM) at 164.2p, and Reading (RG), Hull (HU) and Milton Keynes (MK) all near 163.7p. Northern England clusters around 158.3p to 158.5p.

Motorways

The dearest mainland forecourts in the data are motorway and trunk road sites. Forecourts on the M74 and M1 were charging 186.9p to 187.9p for petrol, roughly 27p above the national average, or about £15 extra per tank. Filling before you join, or at a town a mile off the junction, remains the single largest saving available to most drivers.

What Actually Helps

Advice is only worth giving if the numbers support it. These do.

In a rising market, do not run the tank down

With 98.3% of forecourts raising prices over a fortnight, and petrol up 3.1p in the last week alone, deferring a fill has been costing money rather than saving it. On a 55-litre tank, last week's delay cost about £1.70.

This is advice for current conditions, not a rule. In June the opposite was true and drivers who waited were rewarded. The signal to watch is the wholesale trend, not the number on the sign.

Do not drive out of your way for a cheap forecourt

A car returning 45mpg burns roughly a litre every 10 miles. A 10-mile round trip costs about £1.63 in fuel at today's prices. The supermarket advantage on a 55-litre fill is currently about £1.45.

At the moment, in other words, a ten-mile detour to a supermarket loses you money before you account for your own time. The saving is real when the cheaper station sits on a route you were already driving. It rarely survives a diversion.

Check before you commit, not after

Because the national spread is 58p and neighbouring forecourts routinely differ by 10p or more, a 30-second check before setting off is worth more than any driving technique. The UK fuel price index tracks the national picture, and the map shows live prices near you.

Diesel drivers have had the worse month

Diesel now sits 19.6p above petrol, and it has risen 16.0p in 30 days against petrol's 10.7p. It fell harder in June and has rebounded harder since. Diesel is the more volatile of the two fuels at present, which strengthens the case for filling on the way down rather than waiting on the way up.

On the September duty rise: plan, do not panic

An extra 1.2p per litre is about 66p on a tank. That is real money over a year, roughly £8 to £12 for a typical driver, but it is not a reason to queue on 31 August. Ordinary week-to-week wholesale movements have been several times larger than this increase all summer.

The December and March rises, and the return of annual inflation indexation from April 2027, matter considerably more over time than the first 1p.

A Note on Forecourt Staff

Everything above points the same way: the number on the sign is set by crude oil markets, wholesale supply contracts and tax. Duty is legislated at Westminster. At supermarket and major-brand sites the pole price is set centrally, often hundreds of miles from the forecourt itself.

The person behind the till has no say in any of it. They cannot change the price, they were not asked about it, and most mornings they find out at the same time you do.

Both the Association of Convenience Stores and the shopworkers' union Usdaw report that verbal abuse of retail and forecourt staff remains well above pre-pandemic levels, and sharp price rises are a predictable flashpoint. A fortnight in which 98.3% of forecourts put their prices up is exactly the kind of stretch where that lands on someone who had nothing to do with it.

If a price makes you angry, the outlets that can actually change something are your MP on duty, and your custom going to a cheaper forecourt. The cashier is neither.

The Short Version

Fuel is meaningfully more expensive than it was a month ago, and it got there quickly and almost universally. Petrol has now passed where it stood in the spring, and diesel is closing on it fast.

Crude drove the move, tax adds a little more from September, and neither is something a driver can influence. The 58p spread between the cheapest and dearest forecourt is. That is where the money is.

All price figures in this article are from Fuel Finder's database on 3 August 2026, covering forecourts in the government price feed that reported within the previous 14 days. Crude oil figures are US Energy Information Administration daily Brent closes. Duty rates and the phased increases are as confirmed at Autumn Budget 2025 and published by the Office for Budget Responsibility.