UPDATE 6/7/2014: The FAQ got updated with all the values, so here’s the final fancy verison.
Just got Mario Kart 8, and I made a nerd table based on the data from this FAQ (values multiplied by 4 to make them whole):
In Mario Kart Wii, the stats basically added up to “use Funky Kong on the Flame Runner”, but there’s no all-around best on Mario Kart 8 — the bottom line seems to be “drive what you like”.