Does anyone know what all season or winter tires would fit the stock 18" wheels on the 2007 Infiniti G35 Sport. Thanks.

 

Slick , a suggestion for winters.
Your rims are staggered (8.5 and 7.5" wide) as are the tire sizes (225/50R18 and 245/45R18)
For winter tires I would go with the same size tire front and back. I checked tire rack ( http://www.tirerack.com/tires/SearchTires.jsp ) and they carry Blizzak LM22 or Dunlop M3 snow tires in a 235/45R18, both of these are awesome snow tires.

or, I think it would be better if you just pick up some 17" rims and put winters on them for your winter set-up.

If I get the 07X, I will put snows on the 07 17"ers and I will run my 05/06 Sedan 18" sport wheels in the summer

 

These are the same as the front tire size (225-50-18):
Bridgestone Blizzak LM-25

There are a bunch in the rear tire size (245-45-18):
Rear-Size Winter Tires

 

I saw that for the front but they don't have LM25 for the back in the larger size only in LM22 for the back. That is why I didn't suggest that. It is much better to run the same tread pattern front and rear.

 

I think the name of the game with winter tires is to go skinny so as not to plow through snow but bite, but that depends on how much snow you really expect. The other thing is these tires have a very tall sidewall, i.e. 50 and 45 series--quite unusual in this day and age, which will add up to more limited fitments. Because they're relatively tall already, I'd probably not go -1 to a 17". But if the car were running 35's and 40's say in a 255/225 combo, going from 18 to 17 would be very practical. Also be careful, if the G35s has sensors in the wheels, you'll need to purchase those as well on your winter setup--probably another $150 to $200 for the 4.

I'd say less snow = direct replacements (245/225). Seemingly not mass marketed are the Hakkapeliittas of various types, but ask any New Englander. If you're really serious about snow, you wont want 245's in the rear, you'll want something skinnier like what would be on the non sport car and probably = the front.

 

Agreed, I would not only say better, but essential that all 4 corners match. There is never any reason to have differing tires on the 4 corners, that will change the behavior of the vehicle.

 

will 245 fit on all 4 wheels?

 

Your 07 18" wheel widths are 7.5" front and 8,5 rear

Yes.
If you went with a 245/45R18, the reccommended rim widths are usually 7.5"-9"
No
If you went with a 245/40R18, the reccommended rim widths are usually 8"-9"

I just went by tire manufacturer's reccommendations. Some people do run the lower profile tires on this size rim but you will get more sidewall bulge.