Hello, This is my first post. I am about to buy 20" rims; 20x8.5 and 20x10. I am wondering if 245/35/20 and 275/35/20 are to large for a non lowered car? I am also thinking about 285/30/20 rear. By the way, this is a GREAT place to learn about my car. Thank you

 

Welcome.

Of course you used one of the calculators above and compared the new tires to the OEM tires. What did you find?

 

I found front of 26.7 vs 25.9 and rear 27.6 vs 26.3. I know that is a little off of the 3% that is recommended, and that bothers me. It also bothers me that there are wheel companies that recommend those larger sizes and just say, "we put those on all the time". I don't mind going bigger if there aren't to many adverse effects.

 

For 19's, the "standard" size is 245/35 and 275/35. For 20's, you'll have to go down one more step, like 245/30 and 275/30. You'll need to check the diameters of the tires you're looking at to make sure they stay pretty close to the stock ones. There are other combinations that will also work, for example I'm using 255/35/19 and 285/35/19. Since diameters can vary slightly, check the sizes for specific brands to make sure you're picking compatible ones.

Check out this thread:
https://my350z.com/forum/wheels-and-tires/119204-20-wheel-and-tire-discussion-thread.html

It's the 20" Wheel thread with lots of pictures of 20" wheels on Zs. You might get some hints and ideas on tires sizes by browsing it.

 

Already checked. The best fit is 255/30/20, 275/30/20. I would probably get 285/30/20 if I go that route. I thought I'd try a little more sidewall to help with rim bends. When I look at the twenty inch thred, however, I don't see a lot of thire sizes on it.

 

Might also pay to take into consideration changing rims size will change your rolling radius, can cause a few niggles with your traction control.

 

That's why he needs to go down one step in tire profile. The 245/275 sizes work on 18's with 40 series, on 19's with 35 series and most likely on 20's with 30 series. That help keep the diameters about the same.

 

Never mind. Just bought 19's