Found a set of 18x8.5 +15 offset wheels that I am considering.

Question is, would 18x8.5 look ok? I know most Z owners run staggered setups...

Also I guess the recommended tire size would be 245/40/18 on all four.

Thanks for the help!

 

245 on all four is fine, plenty people run a square setup in place of the factory width staggered one, you'll get a bit of oversteer compared to the mildly understeering original setup on Zs.

245/40 R18 on all four though doesn't have the diameter staggering that VDC expects, so that WILL give you problems.

245/40 R18 in the front and 245/45 R18 in the back is more in line with what VDC expects.

235/40 R18 front and 255/45 R18 is also fine on 8.5 all around and should be within the VDC tolerance if you want to keep the understeering behaviour of the stock Z measures, although you're running a bit tall in the back and the speed readings might result a very slightly off.

235, 245 and 255, with 245 being generally ideal, all fit well on 8.5 without excessive pinching or stretching, with the obvious slight differences different tyre makes and models will have.

 

18x8.5 all around works.
I do not recommend 245/40/18 on all four.

 

i have 18 x 8.5 all around

i kept stock size tries tho

225 and 245

 

Thanks for the help/info everyone! I will keep this in mind if I do indeed pick up the wheels.

 

18x8.5” wheels “all-around” is a good choice. That allows more choices in tire selection than 8.0” wide wheels. If you go with 245mm tires, they will look about perfect (not bulged and not stretched, but 8.5” wide wheels allow choices past 245mm wide).

As davidv mentions…
…you should not go “all-square” with 245/40-18”. It’s just not the right size for all-square.

If you go ‘all-square” (you only do this to allow rotating tires and maintaining even wear), mount something like 245/45-18” all-around. A better wheel/tire setup is 245/40-18” front and 245/45-18” rear.

When (if I guess since you're still considering this) you get your new wheels on your car, please post some pics.

--Spike

 

Hi Spike.

What would be the disadvantage of running a 245/40/18 on all four? The guy that I am looking at getting them from, used this setup. Haven't asked what his thoughts on the setup though.

I have TCS but no VDC, i'm enthusiast model. There is a difference in the VDC vs. TCS right? (Sorry for the newb question, I haven't researched too much about VDC.) I am not worried about not being about to rotate if I do use different sizes. So would it be "best" to a different size F vs R?

Thanks for the help!

 

^^ My recommendation to avoid 245/40-18” “all-square” is based in the problem reports other members have posted here running this setup. However; and if I remember correctly, these problem reports come from members with a VDC-equipped car.

I cannot provide personal experience with the equivalent overall diameter of 245/40-18” on a TCS-equipped Z since I never ran this size on my Enthusiast.

I can say that 245/40-18” is a problem on VDC-equipped Z since I’ve run the equivalent overall diameter on my VDC-equipped Performance model, and it doesn’t work 100%. This setup is good most of the time… but when it’s bad, it’s very bad.

I cannot provide additional information here other than I would not run 245/40-18” (but, that’s based upon my experience with a VDC-equipped Z).

--Spike

 

VDC will go nuts on you if you don't stagger height because the return in rpm and torque differential to it with unexpected diameters computes like a slip.
Square setup on width shouldn't have any effect at all.

 

^^ I have a 2003 Performance model (and thus VDC).

I’ve run “all-square” (same overall diameter and tire width) with my winter wheel tire setup (225/55-17” on all corners) for two seasons now, and no problems whatsoever.

I have tried 225/50-17" all-square, and also 245/40-18" all square, and this overall diameter failed with my car's VDC.

--Spike