Fuel Use

In the ship design rules, a standard load of fuel lasts 600 hours. That seems to be regardless of the speed of the vessel. So, my rule is its 600 hours for a speed class 4 vessel. So for example, a speed class 8 vessel would only get 300 hours of flight time, a speed class 2 vessel would get 1,200. To calculate, divide 2400 hours for the base fuel use (600 hours x 4 speed class) by the ship's speed class. So a speed class 3 ship would have 800 hours of fuel.
Activating pulse drive uses up 25 hours of fuel per speed class, doing a hard burn doubles your fuel use.

For vehicles, they get 60 hours for a standard load of fuel. The justification is that the small power plants in vehicles are not as efficient as the large ones aboard spacecraft. And partly it was because I didn't like having ground cars with 60 hour or more fuel supplies.