Think about it ...
The least amount of gas you can take is 25%.
A sector is 25 miles square.
How many sectors would one have to drive to empty 25% fuel in whatever vehicle that you take ?
Who in hells bells would care to drive the distance, in a vehicle, to try an empty the fuel tank, considering the speed at which these vehicles travel.
I don't think there is anything wrong with the fuel consumption in the vehicles ... there just is no need or case to have to drive one far enough to run out of fuel.
I would rather stick sharp pencils in my eyes than try to prove/disprove this tho.