After seeing this question about the time-travelling range of the DeLorean, the consensus was that it was merely restricted by the controls (a 4 digit number, giving it a range of 0-9999).
However, the goal of Back to the Future 1 was to give the Flux Capacitor enough (electrical) power to function correctly; at the end of BttF 2, when Doc Brown arrives and tells him he needs to go to the future, he starts rooting through the trash for fuel; and then in BttF 3, the gas tank gets punctured, (effectively) stranding them in the past.
So my question is - does the time travel require "fuel"? Or is it just for the driving around town?