I know it's hard to believe, the the low-end MBA has a Core i5 processor. https://www.apple.com/macbookair/features.html Apple worked directly with Intel to get a smaller "package", and soldered it to the mainboard to make it fit.
That's interesting, I've got a Core 2 Duo which I assumed would be similar to the i3 in terms of power. I guess it shows that processor versioning is more than just marketing.
I don't know what a MacBook Air uses, but given that it's a notebook probably something slower :)