The main service station north of Vilanova on the way to Vilafranca isn't actually on what is now…read morethe main road (C-31), but on the old main road, just past the suburb of Tacó and adjacent to the cement works. (The location isn't quite as grim as it sounds, but nor is it at all scenic - but do you care for a petrol station?)
Petrol and diesel are roughly the same price as in other main road service stations (Cepsa have 3 others in the town), and it has a car wash and a small 'mini-shop' shop selling the usual range of minor car accessories, confectionery, drinks, magazines and small household goods (tissues, shampoo, that sort of thing).
It also has a large, accessible toilet inside the shop.