The rims' size for my Z is 18, I wanna make it bigger, but some of my friends told that better dont change the size of the rims, and it's not good for the car. So, is there any limite for the rims of 2007 Z?

 

Your friend is not very smart.

 

It's actually very bad for the car. Your warranty will void right away, the car will break down immediately, and the dealer will slap you when you bring it in

 

way to choose a group of friends...

 

your friend needs to get run over by your wheels

 

Its not bad for the car by any means. Optimum size would be +1" bigger and lighter in weight. The thing about going up in size, is when you increase in tire size, especially hitting the 19" sizes, they get pretty pricey and not much selection in the width/sidewall aspect ratios in that size.

 

What looks good and what performs good are usualy two different things. Many people opt for either lighter 18s or lighter 19s vs stock. With lighter 18s you can still get cheaper tires and have a broader spectrum of tires to choose from. Keep this in mind, even the RS380 concept runs 17'' rims in the front, 18s in the rear. Most performance minded people will runs 18s all around.

 

Welcome.

Big heavy wheels are detrimental to performance. But no one cares. Maintain the same overall tire height. 19 and 20 inch wheels will fit.

 

+1.