Rontec Magor, NP26 3YL. A motorway service area, where you have no choice.
What it is charging
Unleaded: 177.9p a litre, 6.2p over the national average, filed Tuesday 27 October
Diesel: 205.9p a litre, 7.2p over the national average, filed Tuesday 20 October
Super unleaded: 197.9p a litre, filed Tuesday 27 October
Super diesel: 225.9p a litre, filed Tuesday 20 October
Unleaded within 5 miles
Caldecot Fuel Express Automat: 167.7p a litre, 3.6 miles away. 10.2p a litre cheaper: saves £5.61 a tank, and costs about £1.37 of fuel to get there and back. Worth the trip.
Nts Manor Garage Service Station: 167.9p a litre, 2.7 miles away. 10.0p a litre cheaper: saves £5.50 a tank, and costs about £1.03 of fuel to get there and back. Worth the trip.
Hillcroft Stores: 171.9p a litre, 2.9 miles away. 6.0p a litre cheaper: saves £3.30 a tank, and costs about £1.13 of fuel to get there and back. Worth the trip.
Newport Spytty Extra - Petrol Filling Station: 172.9p a litre, 4.7 miles away. 5.0p a litre cheaper: saves £2.75 a tank, and costs about £1.84 of fuel to get there and back. Worth the trip.
Newport Chepstow RD Esso Express: 173.9p a litre, 4.4 miles away. 4.0p a litre cheaper: saves £2.20 a tank, and costs about £1.73 of fuel to get there and back. Worth the trip.
On a 55-litre tank at 40mpg. The distance is straight-line rather than by road, so a real trip is longer than the one costed here.