In our eligible UK sample, motorway-service prices averaged 19.5p/l more for E10 petrol and 17.1p/l more for diesel than non-motorway prices. Whether a different stop saves you money also depends on access, extra driving and the amount you buy.
Analysis by Route & Fuel editorial team · Published 5 September 2026 · Snapshot at 20:36 UTC on 4 September. This is a dated study, not today's local price list.
Each station counts once per fuel grade. These averages are not weighted by fuel sales.
| Fuel | Motorway stations | Motorway average | Other stations | Other average | Difference |
|---|---|---|---|---|---|
| E10 petrol | 101 | 183.81p | 4,903 | 164.31p | 19.50p/l |
| B7 diesel | 73 | 203.01p | 4,702 | 185.89p | 17.11p/l |
The source contained 8,052 unique stations, including 168 with an explicit motorway-service flag. After the checks below, 5,304 unique stations supplied at least one eligible E10 or B7 price. The petrol and diesel samples overlap; their counts must not be added to estimate unique stations.
A pooled national difference can reflect geography, brands and the stations that supplied eligible data. It does not establish the effect of motorway location on price or what any individual driver will save.
For each eligible motorway station, we found non-motorway comparators within five miles in a straight line. We required at least three comparators and compared the motorway price with that local group's median.
87 motorway stations had enough comparators; 14 did not. Across those 87, the mean difference from each local median was 19.24p/l. There were 730 distinct local comparators.
81 of the 87 motorway prices were above their local median. Some were cheaper: differences ranged from −7p to +30p per litre.
60 motorway stations had enough comparators; 13 did not. Across those 60, the mean difference from each local median was 16.64p/l. There were 599 distinct local comparators.
56 of the 60 motorway prices were above their local median. Differences ranged from −3p to +28.6p per litre.
Nearby stations can be on the other carriageway, beyond a junction or separated by a river. We did not test road access, opening hours, traffic or tolls. A station can be a comparator for more than one motorway site. These are geographic comparisons, not measured route diversions.
The following is a modelled example using chosen inputs. It is separate from the observed station comparisons above.
55 litres, a 10p/l cheaper alternative, 45 UK MPG and an alternative fuel price of 165p/l.
Gross price saving: £5.50.
Five total extra miles compared with the original journey use about 0.505 litres.
Extra fuel cost: £0.83. Saving after extra fuel: £4.67.
Allowing 10 extra minutes at a chosen time value of £12/hour adds £2 to the comparison.
Saving after fuel and this time allowance: £2.67.
Gross saving (£) = litres bought × price difference (p/l) ÷ 100.
Extra fuel cost (£) = total extra miles ÷ UK MPG × 4.54609 × alternative price (p/l) ÷ 100.
Saving after the detour (£) = gross saving − extra fuel cost − chosen time cost − extra fees. Count all additional miles, including the return leg when needed; do not use the one-way distance from a search pin.
With this example's inputs and no time or fee allowance, the fuel-only break-even point is 33.0 total extra miles. This is a mathematical threshold, not a suggested diversion. The downloadable table tests 288 combinations of fill size, price gap, MPG, extra miles and time value.
Exclusions matter. Unknown closure status excluded 1,379 stations before grade checks. The seven-day rule then excluded 1,460 E10 prices and 1,791 diesel prices. A price that has not changed for longer may still be valid; this conservative window changes which stations are represented.
Using the same method with a 24-hour window gives national gaps of 17.94p/l for E10 and 20.55p/l for diesel. With a 30-day window they are 19.54p/l and 17.60p/l. The result depends on the eligibility window; use the full counts in the summary when comparing these figures.
This is a filtered snapshot, not a random sample or a sales-weighted UK average. We have not independently audited each source flag or pump price. We do not give a confidence interval: correlated stations, shared comparators and selection bias would make a simple interval misleading.
Planning a motorway journey? Read the practical motorway fuel-stop guide and compare stops on your route before choosing an exit.
The downloads contain derived statistics and modelled scenarios. We retain the source snapshot and analysis code for reproduction and corrections; its filename and SHA-256 fingerprint are recorded in the summary. Raw station records are not included in these downloads.
Source: UK Government Fuel Finder API guidance. Read our fuel-data attribution and editorial and corrections policy.
For a current buying decision, search nearby fuel prices. For other dated findings, browse our fuel price reports.
