There's like 16 different kinds of Mobil 1!!

So I was at the local AutoZone today picking up supplies for an oilchange, and on the shelf where there's usually two different weights of Mobil 1 (I've been buying the 10w-30 with the green cap) there were no less than five different varities.

A couple that I can remember were "european car formula" and "performance driving formula." The latter of which I'm sure is a big seller with the Import Kids who only have to buy 3 quarts of it for their little 1.8-liter four bangers

Anyhow, both the European formula and the Performance formula were 0w-xx Can someone please just give me a brief oil weight explanation and then do their best to elaborate a little on whether or not this "performance driving" Mobil 1 is just a bunch of snake oil BS?

-Adam