Only 7p?
Motorway services have shocking price markups, way more than 7p. Most people don't realise this or are just too lazy to find something that isn't quite as convenient.
According to the live feed at https://www.rac.co.uk/drive/advice/fuel-watch/ I see:
Unleaded is 131.80p (UK wide) and 156.80p (Motorway Service Area).
That's nearly a 20% markup.Last time I drove into a motorway services and saw prices ~20p/litre higher I just drove through the petrol station and found a local garage to fill up at.
Spending an extra £10 once or twice a year when driving a few hundred miles and thus needing to fill up at a motorway is nothing. Chances are I’m spending that much on an overpriced coffee when I do that anyway.
Ironically I had to do a small topup on the M4 today, and yeah, that was mad!