Hi Guys i recently bought 20 in. rims for my 2006 g35 coupe

I was wondering if you guys could help me with tire Dimensions?
I have talked to a tire specialist and he told me to go with
(235/30/20)in the front and (275/30/20) in the rear

But im confused because i see alot of guys put (.../35/20) in the front and (.../30/20) in the rear

What would be better 30sidewalls all around or 35 in front and 30 in rear
and are there any pros cons to either, and what would be the difference

Thanks for all your help guys appreciate it !!!!!!!!

 

1. the first number is the width of the tire.
2. the second is the length of the sidewall BUT it is simply a percentage of the width of the tire.
3. the third number is the rim size.

so the specialist told you to go with:
235mm tire width / 70.5mm sidewalls on the front (235 x 30%)
275mm tire width / 82.5mm sidewalls on the rear (275 x 30%)

sounds like your car will have its back end raised higher than the front. usually rear tires are supposed to be wider on RWD performance cars for more traction. the people who did (.../35/20) fronts and (.../30/20) rears probably didnt want their back end higher than the front end, so they had lower sidewall on the front. on my Z i had 245/35/20's on fronts and 255/35/20's on the rears and it didnt seem to offbalanced. idk I am by no means an expert, just sharing the info I have learned :]

FYI: I see your in Chicago, if you get 275/30/20's on your rears I HIGHLY suggest you change em back out for your stocks in the winter. wide tires grip the road but also allow you to hydroplane much easier! I lost my Z because i hydroplaned so easily @~30mph, yeah the Gs heavier but its still just as dangerous, especially w/ those suuuper wide *** tires lol! My Z was my baby! I would hate to see anyone lose their car like i did, SO PLEASE BE CAREFUL!!!!

 

235/30/20 is much too small and will actually cause your VDC to trip out.

You're going to want a 245/35 up front if it's paired with the 275/30.

Everything trickstyle said is thumbs up.

 

On my 03 Sedan I am running 225/35-20 on the fronts and 265/30-20 in the rears and to date this is the best setup I have installed. I had your setup and even more aggressive rear's. Either i couldn't get the car aligned to spec or the drive-ability was hindered in one aspect or another.


my current setup vs my OEM setup



this is your setup vs your OEM setup

 

We will typcially run a 245/30-20 front and 275/30-20 rear on a coupe.