Will it make it?

I'm due to pick up my new car on Thursday and as you can see here my old car is telling me I have 15 miles still left in the tank. Between now and Thursday I have three 6.7 mile journeys to do as well as avoiding whatever roadworks that Edinburgh council will throw in the way. So who would go for it and not add a splash more fuel and who would risk it?

Do pilots have the same thought process when they are doing internal flights? "I know its 300 miles to Edinburgh but the gauge says 290 miles - there's always a bit extra in there than the gauge says..."