Want to know, are petrol stations open on good friday ? well check it out guys! ;) most of country usually have different regulation! but most of them are always have clear cut rules i.e some industry are allowed to open, even on restricted trading day or weekend! thanks god, petrol station, oil, car parts and etc are allowed to open on restricted trading day. the reason simply because most of people will need this kind of services,or goods! because even on weeken or holiday some people will use a car to travel from one location to another!
So, you don't have to worry even on good friday, petrol station will be open! but for some cases, it can be closed, because it will depend on the owner! if the owner want to closed on good friday, what can we do right ? but for business profit closing on good friday maybe its not good idea, I mean they have to make money right ? but government regulation allowed petrol station open on good friday! that's the good news!
my suggestion is, if you want to travel for long distance, try to buy petrol before good friday! just to minimize the risk! because if petrol station are closed down, you don't have to worry because you already save the fuel for tomorrow! but if you don't have preparation, try to use or borrow a car that have full fuel! I am sure it can solve your problems :)