You want to compute how much you spend on fuel over time? I first used a spreadsheet, then fuelly.com. It allows me to see my average MPG, average fuel price, total paid for fuel, etc. And records (or I enter it really) the amount of fuel I buy and what I paid for each unit of fuel and then computes or even graphs all the other items I might want. Even gives me a signature display like it should show below. And yes, it does L/km. I doubt it does takas.
There is no way to do this on the V as far as I can tell. I did have this feature on the regular 2013 Prius. It was nice because it would display your cost for the trip after you shutdown.
