Which wheels do you have on your I30? If it's a touring you have the 17" wheels, if it's not a touring you have 16" wheels.
IIRC, stock sizes in your year are 215/55/16 or 225/50/17, but I could be wrong... (is it 215/50/17?)
Fitment is the same as the Maxima of the equivalent years, the stock 16x6.5" wheels can't fit wider than a 225 tire, so to maintain overall rolling diameter, 215/55/16 is best, while 225/55/16 is a little too big and 225/50/16 is a little too small. I prefer the larger 225/55/16 size as it fills the wheel wells a little better.
For the stock 17x7" wheels you can't fit a tire wider than 225 or so with such a low profile, although some
have fitted 235/45/17 or 235/50/17 tires successfully. If stock size is a 225/50/17, you're probably best off sticking to that size. You can run the wider 235's, but due to the low-profile sidewalls they'll look funny as they get stretched in kind of ugly ways.
All-season tires... the usual. Bridgestone RE950, Yokohama AVID V4s, Yokohama AVS dB S2, Dunlop SP5000... Falken Ziex ZE-512's are technically all season as well, although their directional tread pattern is a little aggressive for snow. I'm more familiar with summer tires, as I live in a place where you have to drive several hours to visit snow.
