18" tire optios from Pirelli:
Pirelli P Zero Asimmetrico N2 (Carrera 4) And N3 (GT2 And Carrera)

I have N3 all around, rears are worn. If I pick up a set of N2's will it be ok?

Trying to save $ on current tires since I will be buying a set of 19" wheels sometime soon.

 

you know... I was told that the front tires should match the rears. The number following the "N" simply denotes the chronology in which that tire was given the "okay" by porsche - generation is a better word, if you will. Check out tirerack.com for more info...I ended up just forgetting all of the "N" spec junk and got re050a pole positions all around and i couldnt have made a better decision...

ps. just because tires arent n spec doesnt mean theyre bad tires...

 

Don't mix, just match rears.

 

This sounds right...denotes the generation, but if the model is the same, I would assume it'd be okay.