Need some tire size advice please.

[Portlis]

Hey guys, I'm just looking for a bit of quick advice about tire size. I greatly appreciate any help I can get.

I've got a 370 with the sports package. I just purchased a set of the standard 18" wheels for winter from fellow forum member Texmedic, as can be seen here:

Base 18s wheels only

As AK pointed out in that thread, tirerack has some blizzak LM-25's on sale right now for $162 each. I'm very interested in getting these, but the one thing that confuses/concerns me is tire size.

According to Nissan, the specs on the base wheels are 225/50/R18 front and 245/45/R18 rear.

Now, the tires that are on sale for that $162 are the 225/50/R18. Am I correct in assuming that I can put 4 of these same sized tires on the base 18" rims and it will work just fine? Or do I need wider tires on the rear wheels?

I'm still trying to learn as much about this stuff as I can, so please bear with me here and thanks in advance for any advice I can get!