Hi all, new here.
I have an 07" 350z all stock, has 225/45/18 on front and 245/40/18 on the rear. (I think, I might be off on the sidewall, 40/45.)
I know with many wheels you can go a little larger with tire size's, I was wondering if I can go 245/40/18 all around rather than the slightly slimmer tires in the front.

Thanks for any information.

 

Depends on the trim level (or more importantly, whether your 33 has TCS or VDC - guessing it does based on the wheels and your existing tire setup. You must maintain that ratio F to R. 245/40 up front is a good upgrade (with zero issues) on stock wheels. For the rear however, you need to either stick with the 245/45 for the height or go to a 265/40 or 275/40 to keep the height. 265 is slightly shorter than stock height but, will fit the OE wheel whereas 275 is a tad large for an 8.5" wheel. But people have done it with no issues, just not exactly optimum.

 

Thanks for that information.
So, I'm just thinking out loud,
My initial inquiry was to determine if I can use the same size on all 4 wheels to simplify tire buying and rotations.
But, if I can't do that, or even if I can, I did want to consider possibly going another way, just for the looks and a little added grip, going wider on all four tires, using stock wheels, not necessarily the same size front and rear.

Here are a couple scenarios trying to figure out which would make more sense or if either is even possible.

If I went 245/40/18 all around, for simplicity's sake and to be able to rotate tires, I would throw off the speedo a little since stock the rears are 245/45 now, but anything else detrimental to the stance or the cars performance?
The difference is 5 mm so around 3/8"of an inch.

Or what if I upgraded the front to 245/40 and went 275/40 in the rear, this doesn't change the tire rotation issue but would probably look a little better and I'm guessing slightly wider tires means a little grippier on the road?
And this doesn't seem like an issue for the speedo either, correct?

Sorry, just trying to make sure I understand.
Matt

 

Re-read my earlier post.

If you have any trim other than Base, you have either TCS or VDC (both forms of stability control).

You must maintain the proper stagger F-R, 3% give/take else wheel speed sensors will tell the ECM your back end is sliding and trigger a Slip warning and put you into limp mode.

Rotation.... not something the Z gets. Resign yourself to buying tires.

 

Your rear tire needs to be taller than your front tires to keep your traction control system happy. That said, going 245/40 all around for simplicity's sake will run the risk of throwing different lights on your dash (abs/ VDC/ SLIP) so to avoid that if you're doing 245/ 40 front, stick to the OE 245/45/18 size for the rear. I also would recommend not going wider than a 255 tire for the rear, anything bigger than that on a stock 18x8.5 might look funny.

 

Ya, 255's on 8.5" would look CRAZY
275's on my 8" wheels

 

Those look beautiful.