I had a question regarding 19" tire sizes. I have an '08 G35 sedan and am not lowering my car. The recommended sizes to stay close to the OEM 18" tire diameters are: 245/40/19 (F) and 275/35/19 (R). I'm wondering if I can do 255/40/19 (F) and 285/35/19 (R) to fill in the gap better? Here are the diameter specs I found using an online tire/wheel calculator:

OEM
225/50/18: 683 mm (26.9")
245/45/18: 677 mm (26.7")

Option #1 (recommended)
245/40/19: 679 mm (26.7")
275/35/19: 675 mm (26.6")

Option #2
255/40/19: 687 mm (27")
285/35/19: 683 mm (26.9")

Compared to OEM tires, Option #1 is smaller by 4 mm in the front and 2 mm in the rear. Option #2 is taller by 4 mm in the front and 6 mm in the rear.

Tire places claim with Option #1, the diameters are close enough that our traction control, ABS, etc. will not be compromised. So isn't Option #2 close enough as well???

 

both are close enough to stock that it won't matter. Go with the wider widths

 

Either way would work.