Anyone who has pulled into a motorway service station with the fuel light on knows the feeling: the price on the pump is noticeably higher than at the supermarket near home. That isn't your imagination. The Competition and Markets Authority (CMA) has measured the gap repeatedly, and it is wider than it was in 2012.
The good news is that, for most journeys, you don't have to pay it. A little planning before you set off usually does the job.
The short version
- Motorway forecourts are consistently the most expensive places to buy fuel in the UK.
- The CMA puts this mainly down to weak competition: sites are far apart, often run by a small number of operators, and you can't see the price until you've left the motorway.
- Service areas also have to stay open around the clock and offer free facilities, which adds to their running costs.
- The simplest fix is to fill up before a long trip, or plan a stop at a cheaper forecourt just off a junction.
How big is the motorway premium?
The CMA has measured it several times. The figures below are its own, for the periods stated.
| Period | Petrol premium | Diesel premium | Source |
|---|---|---|---|
| 2012 (OFT study, at 2022 prices) | 9.5p a litre | 10.5p a litre | CMA final report, July 2023 |
| 2022, on average | around 20p a litre | around 15p a litre | CMA final report, July 2023 |
| 11 March to 13 April 2026 | up to 26p a litre | up to 17p a litre | CMA monitoring report, May 2026 |
The 2026 figures are the largest daily gap between average motorway and non-motorway prices over that period, so on many days the difference was smaller. Even so, the CMA worked out that at the top of the range the premium came to roughly £14 on a 55-litre tank of petrol, or over £9 for diesel.
Why motorway services charge more
Weak competition
This is the main reason. In its 2023 market study the CMA said motorway forecourts are "placed at some distance from each other", that opening new sites on existing stretches of motorway "is generally unlikely", and that the supply of fuel at service areas "is concentrated". Its May 2026 report summed it up as "weak competition" caused by the distance between sites, the concentration of operators and "poor visibility of prices".
You can't see the price until it's too late
The CMA also pointed out that drivers "do not see the price of fuel at an MSA until they have turned off the motorway", and that cheaper forecourts near junctions "are not signposted from the motorway". By the time you've turned off with a low tank, there's little choice but to fill up.
Most motorway fuel goes on business fuel cards
According to the CMA, typically around 75% of fuel at motorway service areas is bought by business customers using a fuel card. Private drivers paying at the pump are a minority of the trade, and often the ones who stopped because they had to.
Round-the-clock obligations and running costs
Motorway service areas come with rules ordinary garages don't face. The Valuation Office Agency's rating manual lists requirements including services for all motorway users "24 hours a day every day of the year", unleaded petrol and diesel, "free lavatories with public access" and "free parking for two hours". Running 24 hours means shift staffing all year, and the same manual notes that historically operators paid a fixed rent plus a "participating rent" calculated as a percentage of turnover.
Those costs are real, but the CMA's view is that competition, not costs, is the main reason the premium is as large as it is.
How to avoid paying it
Fill up before you leave
If you set off with a full or nearly full tank, you may not need to buy fuel on the motorway at all. National Highways already advises drivers to check "that you have enough fuel for your journey" before setting off, so this is good safety practice as well as cheaper.
Look just off a junction
Supermarket forecourts tend to be the cheapest. The CMA found they were on average up to 8p a litre cheaper for petrol and up to 11p cheaper for diesel than other retailers between 11 March and 13 April 2026 (CMA). If there's a supermarket forecourt close to a junction on your route, a short detour is often worth it. Just weigh the saving against the extra miles.
Plan your stop with a price finder
The "poor visibility of prices" problem is much smaller than it used to be. Under the government's Fuel Finder scheme, around 97% of UK forecourts were registered and sharing their prices by August 2026, according to the CMA. That means you can compare prices near any junction before you get there, rather than finding out on the forecourt.
Don't let the tank run low
The motorway premium mostly catches people who have no choice. If you start looking for fuel with a quarter of a tank left, you have time to come off at a junction of your choosing. Leave it until the warning light and the next service area is usually the only realistic option.
Drive a little slower
Your speed affects how often you need to stop. The AA says driving at 80mph can use up to 25% more fuel than 70mph. Checking tyre pressures before a long journey helps too.
The bottom line
- Motorway fuel costs more mainly because there's little competition between sites and drivers can't see prices in advance.
- In spring 2026 the gap reached up to 26p a litre for petrol and 17p for diesel, according to the CMA.
- Filling up before you leave, or at a supermarket near a junction, is usually the easiest way to avoid it.
Before your next long drive, check what forecourts along your route are charging. PlugOrPump shows live E10 and diesel prices from Fuel Finder data, updated every 20 minutes. Search by postcode or browse fuel prices by town.