Guys, Tomorrow I'm ordering tires for my incoming Z, to be installed pre-delivery. I need to know if my desired size will rub. I would rather not have to roll the fenders. Here's the deal:

'06 Z
Grand Touring Coupe
Keeping OEM Rays
19"x10" rear, 18"x9" front
OEM tires: 265/35 rear, 245/40 front

DESIRED TIRES: Toyo Proxes T1-R. 285/35 rear, 255/40 front

I will keep suspension stock for now, but might lower it by 0.8" sometime later.

Here are Jason's pics of the GTc's OEM rear wheel/tires to give you a better idea.







Since 1"=25mm, looking at those pics it doesn't look like less than an inch (20mm) increase in tire width will make a difference. I am doing this for both looks and increased traction.

Let me know what you guys think. I am ordering them from the dealership (getting a great deal) and want to do so my tomorrow (04/29) by the latest since the car will be here on May 11th

Thanks.

 

all depends on your offset

 

Agreed. But I don't know the OEM Rays' offset, that's why I added the pics.

 

i highly doubt it will rub because stock offsets are usually pretty conservative.

 

i love those wheels...

 

That's my thought too. Also a 20mm/0.8" wider tire means being 0.4" wider on each side of the wheel. That's gotta be easily doable, even with modest 0.8" drop which is bound to come sometime soon in the future.

If anyone thinks otherwise, please chime in soon.

 

Plugging away at the DML calculator, I have just realized that width increase also changes the tire's overall height even if the profile is kept constant, as I plan to of course. Man...do I feel dumb. I am concerned about VDC issues now as F/R overall height is markedly different between OEM and my proposed set-up. Let me know what you guys think after looking at the following:

Stock:



Planned:

 

I've got volk gt-7's (9.5 / 10.5) coming in next week(+30 in front and +24 rear). I'm going with a 255/285 BFG KDW2 setup.

I have to roll my rear fenders.

 

usmanasif

received your pm about concerns about TCS/VDC with your tire choices.

i see you have a 2006 350z. most of the data gathered on this site about TCS/VDC compatability is based on earlier years when the tires offered were front 225/45/18 (26") and rear 245/45/18 (26.7").

i have no clue if the 2006 TCS/VDC is reprogrammed for the 245/40/18 (25.7") and 265/35/19 (26.3"), since these have slightly different rolling circumferences than previous years.

it has been posted in the past the the height stagger should be 0.5" to 0.7" between front and rear for TCS/VDC to be happy. however, it is unknown where that info came from as it is neither posted in the owners manual or the shop manual. your choices are closer to previous years, and so if the VDC/TCS software has not changed, you should be good to go. otherwise, i don't know

my guess, you will be okay with your tire choices for a 2006 model (definitely okay for an earlier year), but don't hold me to it since i'm not familiar with the 2006 VDC/TCS software

hope that helps and not hinders

as to the rubbing issue, need to know the offsets of the wheels you will run to answer that question (i don't know the offsets of the new 2006 wheels)

pp

 

That helps in a big way...thanks a bunch man.

One question I forgot to ask: After using the calculator on Miata's site (from your other post), it's telling me that my speedo will be slightly off with the new tires due to rolling circumference. Is the Z's ECU smart enough to automatically overcome that and readjust the speedo? I don't recall seeing any threads of folks having speedo issues even after changing their wheels, let alone tires, so I am hoping it is not an issue for us.

 

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