In Millau, recently, we paid 109.5/l for diesel. Today it's 112.9. However, at the Aire d'Aveyron at Severac le Chateau it was 127 when we were there, and today it's 132.9 - so today a saving of 20cents a litre, which is still a considerable amount at 12 euros saved per fill-up of (say) sixty litres!