I have a '12 G37xS sedan and it came from the factory equipped with 225 18 50 tires on 18"x8.0" wheels, if memory serves.

I was considering going with slightly wider wheels for a better contact patch and perhaps a slightly better look (probably more a look improvement than a performance upgrade). Just a little wider, but not too crazy.

Would an 18"x8.5" wheel with about a 245 18 45 tire fit the car on all four corners without rubbing? Anyone running this size or similar? I'm not even sure if these particular sizes are available.

My goal would be to have a wider tire but have the outer dimension (to the tread) be the same as stock. I'd really prefer not to go with a lower profile tire (19" or 20") to get the wider wheel.

 

you will not rub. that is the rear size for the sport model (sedan).

 

I've been considering the same thing for my G37X...

 

He's correct. I have 20 x 9 on my car, lowered on coils, and I don't rub unless I really hit a dip hard.

 

I think your OEM wheels are 18x7.5" all around...? My OEM G37S fronts are 18x7.5" and rears are 18x8.5"

A 245-45-18 is a very common size and will properly fit a rim width range of 7.5"-9" so you could actually put them on your OEM wheels to.
It is the correct rolling circumfrence so your speedometer will only be .7% out at 100km/hr.

My summer wheels/tires are 20x10" and 20x8.5" with 275-30-20 & 245-35-20.

 

FWIW, i run 18x9.5 on 255/45 all around. No problems. Might go with 265 or 275s next time, the 255 on 9.5 looks a bit too stretched to me.

 

Sounds like a waste of money to me. Afterall, it is a sedan for heaven's sake, not a Porsche Cayman.

 

Why is that?

 

Yes, please explain...

The 225/50/18 tires are just not the right size for this car. Most other cars out there that compare to the G have wider tires.

I think the 245/45/18 would be just right.

 

What do you really gain for your $800 new tires alone? Seriously.

The OP's topic was wider wheels, meaning additional cost even over the price of the tires. So the wheels would be another $700+. For what exactly? Noticeably improved performance? I rather doubt it.

 

The title was wider wheels, but along with it came the statement of wider tires: 245/45/18 also.

A little better handling, traction, and looks too...

You really think 7 1/2" wheels with 225/50/18 is good for this car? Would 205/65/18 be a good fit instead?

 

Perhaps, when the existing tires need replacement. But not if that size requires a slightly larger wheel purchase. That is my point -why throw money away on new wheels when what is on the car is perfectly fine. Unless you are Donald Trump, in which case money is not of any concern.

 

Well, in that case... I'd better call Vossen and ask if they'll buy these wheels back from me. The stock wheels and suspension sitting in my garage will go right back on tomorrow!

[sarcasm]

 

Correct. 18x8.5 rear, 18x8.0 front.

So... it's been said here that 9.0" width works in the back... will 8.5" fit in the front?

Perhaps. But I bet you sure don't know what your comment sounds like. Poor guy.

 

Earlier 2nd gen sedans were 7.5f and 8r.

18.5" is too wide.

Seriously though, my 9.5's fit, so anything less will work. Just play with the offsets a bit.