Does anyone know if the stock rear wheels on a Sport-package 2007 G35 Sedan will support 275/40 tires? That is, will they fit on the rims AND will they fit in the wheel-well without rubbing.

275/40-18 is 99.93% the same rolling circumference as the stock 245/45-18 tires and the price premium seems minimal for that size.

I was thinking about putting 245/45-18 on the front (the current rear-wheel size) and going to 275/40-18's on the back.

 

for 275/40/18 tires, the minimum recommended rim width is 9.0". therefore, you should not put them on back even if they don't rub. as for front rim fitment, 245/45/18 for the front is okay.

 

i think widest id go is 255 or 265 for the rear. how do you calculate the rolling diameter?? i know theres an online calculator for that but i dont knwo the site.

 

Why would you want bigger in the back? Are you changing the front too?

If you put bigger rear tires on without changing the front you will change the balance substantially.

 

I'm running 255/40/18 on 8.5 rims all around right now with no clearance problems. I have 42 mm offset.
They are .65" smaller in diamter so the speedo will be off some.

 

I have heard that the Traction Control/VDC in the G35 is pretty sensitive to small differences in tire diameter (from Tire Rack, among others). As long all four are the same size, I would expect no problem. But if you had to drive with the compact spare installed, whose size is matched to the OEM tire diameter, you may get all kinds of errors and odd behavior from the TC/VDC. Be interesting to try it sometime before you had to use the spare for real.

 

CFar,

I wasn't thinking about changing only the rear, I was looking at upping both (see the last sentence of my original post).

I'm not even really trying to improve the handling, I just like the look of wider, lower-profile, tires and the tire cost is not that much different. So, in another year, when I have to replace tires anyway, I was hoping to go to 275/40-18 rear and 245/45-18 in the front.

But, from what people have said, and what I found in online research after I started this thread, it doesn't look like the stock wheels will handle tires of that width safely and I'm not really looking to replace wheels AND tires.