With that stated, here's what the chart tells us: for trips of less than 70 miles, the Chevy Volt gets there for less cash. Anything longer, and the Prius Plug-in makes less of a dent on the pocketbook. Makes sense, right? What the chart doesn't show, for some strange reason, is that most trips under 15 miles should cost exactly the same with the two vehicles, since they'll both be using electrons.
Putting the Volt's superior electric-only range against the Prius' exceptional fuel efficiency means that potential consumers should ask themselves one question: "Which is more important for me calculating my driving costs, electric-only range or fuel efficiency?" The answer will depend on what kind of driving you do most days.