Beja: in 1 of 7 places a 50-litre fill-up in Spain saves at least €10 for a detour of 45 min at most; the best is Barrancos (+€14.72, prices of 3 November 2026).
Official prices: Portugal (DGEG) as of 3 November 2026, Spain (MITECO) as of 3 November 2026 · Methodology