Oh how I love charts and graphs! I prefer raw numbers myself, and direct comparisons (here each car is on it's own, rather than each car side by side). But that's me, yours looks much better Sad face because there is no thumbs up face here.

When we get official numbers, I'll get an excel sheet and do a whole bunch of cars and make a big sheet for standard and auto.

I guess the easiest way for consumers to think of it is to take car X, minus the Micra, and write down that value.
Divide that number by the cost of fuel, and that number should be multiplied by miles/gallon.

So buy Car X, or the Micra and get that much fuel included!