And how about 245/40?

 

thread title? 255/55/18? WTF is that?

yes 245/40/18 will fit in the rear.

 

255/55/18 is the wrong size for the 350 Z and should not be used on the front or the rear. Period.

245/40-18” is the right size (overall diameter) for the front (OEM front is 225/45-18”), but this size should not be mounted on the rear. Tire size (overall diameter) on the rear with 18” wheels and 245mm tread width is 245/45-18”. If you want to go with a wider tread (you need wheels that are at least 9.5”), you can mount 275/40-18”.

Of course, any tires with the correct overall diameter for front and rear will work. It’s not the tread width; it’s the overall diameter that is important.

--Spike

 

Exactly

 

Wait, so I need 40's for the front and 45's for the rear? This contradicts what the first reply said...

 

this is not MURANO fourm

 

Thats becase r_seng doesn't know WTF he's talking about. Listen to what Spike100 said, its all correct.

 

A 245/40 will fit the rear fine, but it is far from ideal due to the diameter differential as previously mentioned. I ran 245/40 drag radials with 225/45 fronts with no problems, but VDC will be more sensitive with such short rear tires

 

Same size tires all around with VDC? I think the subject has been addressed a dozen times.

 

you seem to know what you are talking about so i want your opinion ,please help

i am a new 350z owner and it already had Rear 255/45zr18 and Front 245/40zr18 and it was fine with the front bumper lip he had. The owner i bought from gave me the 2 extra tire he had which was the 255/45zr18 (2 was already the rear)

later i decided i wanted a different front bumper and i got it installed etc , made the front really low and caused me problems so i decide to swap the front to the 255/45zr18 and now all 4 are running that. I have no problems with the height etc, but i then realize the gap between wheel and fender were a bit non symmetrical. Before when Rear was bigger than Front it seem okay, but now All 4 are running 255/45zr18, what can change to Rear to make it “ staggered” instead of the car look like its about it lift up from the front.

thanks for your time in advance

 

Seems like a good time for the annual “How to calculate tire diameters and why it’s important” post:

Example tire: 245/45-18 (Stock 350Z 18” rear)

245 tire width in mm

45 aspect ratio (height of sidewall as % of tread width)

18 wheel diameter in inches

To calculate tire diameter - never mind order of operations just input numbers in calc or spreadsheet in this order.

Tread width 245 x aspect ratio 0.45 x 2 / 25.4) + wheel diameter 18 = diameter in inches

Now try that with 255/55-18s to see why your car looks like a 4x4 now. 😆