How is that possible?
Here is my guess on the way it works in GT5, It's because of the angle it acts as being like a wider tyre. heres a crappy image of what I mean, Imagine in the pic you are only looking at the contact area of the trye, if you add toe angle it gives you a larger contact patch.
red line representing the area of contact with no toe angle, blue lines representing the area of contact with toe angle.
I know in the real world adding huge amounts of toe doesn't work the same it does in GT5.