I bought a 07 G35 sedan a year ago. It has G35S 19" rims on it now. I've read some of the stickys and searched around on this site, but cant find any simple answers. I'm gonna be needing new tires shortly and I would like to get a nice set of 20" rims also. Will a 20" rim with a 45 series tire fit without any issues? Do I need any differant offset? Im brand new to these cars and also to wheels and tire upgrades. Thx for any input!

 

Read the stickies. Not only will you find th answer to your questions, but you will also learn a lot.

I dont think that you're going to get a 45 series tire in 20" to fit.
As far as the offset question it depends on the rim width and your suspension set-up.

A 20x10 with a 40mm offset will look a lot different than a 20x8.5 with a 40mm offset.

 

I will try to read the stickys again. I was hoping to find a beginner course or something. Most of the info is a foreign language to me. Im brand new to these cars and was hoping for a simple staight forward answer. I guess Ill try to filter through all the info I dont need and try to find what I do need!

 

Very basic.
Tires what the numbers on the sidewall mean:
255/35/19 for example
255= tire width in MM
35 = sidewall height as a percentage of the width, "Aspect ratio" (35% of 255mm).
19 = rim diameter.
As the tire gets wider (going from a 245 to a 275) you need to reduce the aspect ratio to keep the same overall diameter.
225/40/19's are the same overall diameter as 255/35/19.
Both are 26" tall (+/- .2%). Both sidewalls are about 3.5", but the front (225/40) is 8.9" wide while the rear 255/35 is 10" wide.

So you question about the 45 series tire on a 20" rim would only work if you had a 195/45/20 or around that size ( dont think they make a tire in that size)

A 20" wheel will fit with no problem if you have the proper offset. The offset is the distance from the center of the wheel to the mounting surface of the wheel.

A -0- offset would mean that the part of the wheel that mounts to the hub is exactly in the center of the wheel (from side to side) it is centered between the inner edge of the wheel and the outer edge of the wheel. Positive offset means the mounting surface of the wheel is closer to the outer edge of the wheel (wheel will be closer to the center of the car) while Negative offset means the wheel will extend out further from the center of the car. The mounting surface will be closer to the inner edger of the wheel. The offset is measured in MM.

 

thanks alot for the info 4D! That explains alot.Thx

 

Cornfuzing.

 

Better yet, if you find wheels you like, there is a sticky that is called random questions. Post it in there and someone (probably myself or the guy that just helped you) will be the one to answer it within a few hours or a day or so.

 

The 45 series is quite a bit too large to fit. Typical sizes we see are 245/35-20 all around or 245/35-20 front with 275/30-20 rear.