Q, I think what you have in mind are LED Daytime Running Lights (DRL). Buy an aftermarket set, install, and wire them so you don't need the headlights when it's not dark.
Among the electrical loads in a car is the ECU, which in newer cars can use as much as 100-200W, and there is no way to get rid of it
Though your '94 Golf might not be that computerized, or its ECU may be simple and small wattage.
Oh, and don't forget the injectors and/or spark plugs, plus fuel pumps, etc. No getting rid of those either.
Translating electrical load to fuel consumption isn't easy as it depends on many things. It will change from car to car since different engines have different efficiency. Also, each engine's efficiency changes depending on rpm and load. Electrical load is less efficient at idle than at 2000rpm and 80% load.
What you can do once you reduce your electrical load is to have a switch to disable your alternator's field, meaning it won't charge the battery. You can power it up when you need to recharge, though doing that at home with a charger is better. Or you can turn the field on when engine braking, since then the charging is free. Check out
this thread for more info. Replace the battery with a larger one, maybe even deepcycle.