Work out fuel needed for distance instantly with clear inputs, formula shown and shareable results.
Fuel needed is distance times consumption divided by 100. Usable range is the tank less the reserve you want in hand, and the number of stops is the distance divided by that range minus one, since you start with a full tank.
Fuel required
litres = distance x L/100km / 100; range = usable tank / consumption x 100
Because consumption on the day is rarely the average, fuel stations can be closed, and running a fuel pump dry damages it. Eight to ten litres is prudent.
Yes, substantially. Above about 90 km/h aerodynamic drag dominates and consumption rises sharply with speed.