Okay so I live in the snow belt and I didnt get snows last year and it was a mistake. I am looking at tired but also rim/tire packages. I am finding mostly 16" rims are cheaper and easier to find (esp used). What size will the tire have to be Heighth wise to not get an error in the speedo? Thanks

Oh is it possible to put a larger or smaller tire on the 17" nissan rim?

Here's a calculator for you:
http://www.miata.net/garage/tirecalc.html

Enter your current tire size, and try finding the new size that has the closest revolutions/mile to your current tires.

You have to look at the specs of a specific tire to tell if you can mount it on a certain rim. So the answer is yes, but not every size will fit.

Check out the gen 5 classified ads. Look for "Totalled my max". He has a set of 17 SE with Pirelli snows for sale.

Your profile indicates you have a 2001. You can get get away with 15" with the the correct offset. I am currently running 15" steelies with a set of winter rubber on them (only after I removed my Z32TT calipers/R32 rotor setup in favor of the oem equipment). 2k2+ use larger front brakes, and require minimum 16".

just got 205/60/R16 for my oem rims, cost $129 CAD each for Continantial Viking Contact... good tire is all i can say...

i ran those on my old car...very good for the price.

It's also important to make sure that the tire has the necessary load index and that you'll be able to inflate it such that it can carry the load of your car and not exceed the maximum rated tire pressure.