Stick with 35-series tires on your fronts and rears. You want 275/35 rears....the 30-series sidewalls will be too short in those widths.

 

Already ordered the 30's..The sidewall on the 275/30 should be damn near the same as the 245/35 from my understanding of calculating sidewall widths.. At least that's what I'm double checking (asking).

 

245*.35 = 85.75mm sidewall
275*.30 = 82.50mm sidewall

You're correct in that the sidewalls are close, but Z's come with staggered tire diameters from the factory. So arranging identical front and rear tire diameters should not be your goal. For example the stock 225/45, 245/45 setup has an 18mm difference in diameter between the front and rear. The setup you posted only has a 6mm difference, and in your case it's in the opposite direction being that the rear is smaller than the front.

 

Just because it's staggered doesn't mean the overall circumference is correct. Getting the rolling circumference as close to the OEM has been my goal as I want my speedometer and milage to be as accurate as possible.

None-the-less... I think a 255/35 & 285/35 set-up would be the most ideal depending on wheel offsets.

 

275/35-19 is also a great rear tire size, works well with a 245 or 255/35-19 front. I prefure a 255/275 combo anyhow, why would you want more stagger/understeer than this under steering pig of a car already has.

 

Plus, with a 255 the front wont look stretched on a 9.5, unlike the 245. Ugh.

 

I think you have under and oversteer backwards. And I ran a 255/35 & 285/35 BFG KDW on my 19x9.5/11 and my Z had a very neutral handling aspect. Of course I'm was running Hotchkis springs/sways and could make it oversteer if I wanted.

None-the-less... OP to give you a better answer wheel sizes/offsets would help a lot. And again, with your newly acquired coil overs you'll have better adjustment to help with your rubbing issues.

I'm now running a 265/30 on my 9.5 and looking to go 275 when the current tires need replacement. https://www.facebook.com/AntiStretch FTW!

 

Nope, not my goal, but a temporary fix until I replace the fronts with a 245/30. I just got the fronts last month and at $200 a pop I'd rather get some use out of them.. but if it looks bad, or I notice any driveability issues, I'll bite the bullet and pick up some 30's for the front.. But as mentioned in my original post, coilovers going on today and who knows how that's gonna go with the 285/35 tire on the rear that's getting chewed up already..

 

Thank Robert...wish I knew the specs, when we pull the rims off this afternoon, I'll take a long look for the specs. If they're are none, what's the best route to figure it out?

 

What is the make and model? Unlike the more expensive companies; HRE, ADV1, DPE etc., where you can order your specific offsets; most wheel companies only make certain sizes/offsets. Next resort is contacting the vendor you ordered them from. Last option is getting out the measuring tape.

 

PIAA L'uomo Terzo's

 

Also, they were on the car when I bought it..so I have no clue where they were purchased..

 

I highly doubt you know what a neutral handling car feels like.

 

Yeap.

 

So got the coilovers installed, when I had the rims off I came across the following engraved on the back of the rim. 55DR 19 X 10J 41 not to sure if any of that translates into the offset. Looks good, I am rubbing somewhere on both rears, but by the time I got done, I really didn't feel like messing with the height adjustment. Going to take it in for an alignment today, I'll do it at the shop....

 

You mentioned on the previous page that you have PIAA L'uomo Terzo's. I believe you are actually referring to the PIAA Super Rozza, which say 'L'uomo Terzo design' on the center cap. Is that correct?

If so, then I believe the 19x10 size was only made in +25 offset. I had a set and I was running 275/35/19 Toyo T1-R's on them. They were pretty sunken-in, no chance of rubbing, even if I had a set of 285/35's on them:

 

Yep wheel specs are 19x10 with an offset of 41.

 

^^ Agree. Shouldn't be rubbing the outer fender. Do you have spacers installed?

 

Yes Sir, that is correct.....no spacers... Where the tire rubs isn't the lip, considering I don't see any slicing into the rubber, sounds like It's hitting the plastic fender liner somewhere... However, slicing was occurring on the stock suspension due to body roll while cornering on the opposite side (driver side) than it is now on the passenger side. I'm also hearing a slight tick tick tick from that tire when I start from a stop as the car pulls, once cruising it stops...

 

And I might have missed where you said this, but the rubbing is happening in the rear or in the front?

If the offset of your wheel really is +41 (which I don't think is available in this particular design in 19x10 sizing), but if that's true, then the wheel could be sitting too far in thereby causing the tire to contact the strut, although this is a longshot scenario and I don't even know if it's possible with the OEM type coilovers.