They all start the race with about 100kg of fuel and don't refuel. Apparently that is enough to get the car through the race if tactically driven.
I used to really like F1 but I find it has become a bit boring. I remember going out to Warwick Farm in NSW in the sixties and seeing an Australian Grand Prix with all the top overseas drivers and was completely blown away. I remember Jim Clark came out here and won the Tasman Series and the Aussie GP.
They actually drove the cars in those days, none of this push button, linked up to computers stuff. Those blokes could really drive.