Just to add into the discussion about fuel consumption, I don't believe that there are any rules incorporating driver skill into the equation. As someone noted above skilled drivers make a big difference. They know how to get the best out of their vehicle and that includes improving fuel economy.
I therefore intend to include a house rule of a Driving check to reduce fuel consumption with each success reducing the fuel used by 5%. It's not a massive saving but I suspect that that saving will become important at some stage in the game.
It might be a good idea.