The wheels in question are 18x9.5 +24 Front and 18x10.5 +22 Rear.

Long story short, the "expert" at the wheel/tire shop is strongly advocating tires in the sizes 255/40/18 Front + 275/35/18 Rear for the aforementioned wheels. No argument reference the front, but we had some interesting discussion reference the rear.

We talked, at length, and the "expert" acknowledges that 275/40/18 would match exact dimensions of the OEM 245/45/18 tires. However, in his opinion (largely based on his claims of outfitting dozens, if not hundreds of 350Zs with wheel/tire combos, in addition to his claimed extensive seat time at the track), a 275/35/18 Rear works better. Factors being sited include:

• A 275/35/18 Rear would better match the overall dimensions of the new 255/40/18 Front tire; no argument there, but I don't know how important this is.
• A 275/35/18 Rear would reduce the overall OEM rake (true), effectively "leveling" the car somewhat, allegedly marginally increasing handling.
• A 275/35/18 Rear would provide a bit more clearance. He adds this likely isn't important with an OEM suspension, but should I wish to lower the car, the smaller overall diameter with this size tire reduces the potential for rubbing/scrubbing issues.

If it helps, a couple tables to (hopefully) illustrate my point:

Size 1 245/45/18 Size 2 275/40/18


Size 1 245/45/18 Size 2 275/35/18


Your input/feedback is appreciated.

 

i would stick with 40 series... just look at the numbers, what makes the most sense?

 

I'm inclined to agree with you. The crux of my argument revolves around Nissan's development of the car, whom, I assume, knew what they were doing. The "expert" is insistent that 275/35 is the way to go, based on his experience. Both sizes are readily available and in stock, so it isn't as if he's trying to push what is on-hand.

IMO, I'll sleep better of I go with what was intended.

 

Do you have VDC or TCS?

If yes, your answer is obvious since VDC works on wheel speeds. TCS does as well but isn’t as sensitive as VDC.

 

I do not have VDC, but I do have TCS.

Part of me wonders if I'm making too big a deal of this. Either will work, obviously, but 275/40 feels like the right way to go. On the other hand, I'm gonna feel like a proper idiot if I go 275/40 and it just barely rubs.

 

350Z is 19 years old. In 19 years, the tried and true street setup has been 245/275-40-18 or 255/275-35-19. This has not changed.

Yes, other sizes work including 275/35-18 (so long as you correspondingly drop the height of the front to keep your traction system happy). Some track set ups use a square 275/35 and that works as well if VDC disabled.

Final consideration (if it matters to you)…. Wheel gap is much more pronounced if not dropped.

 

My question would be what are the wheel offsets

 

+24 and +22 per op.

Conservative enough to give clearance of any 245/275 but also afford a good track width gain to add some cornering traction and decent turn-in response.

 

Then I would do 40 series personally

 

For daily driving the 255/40-18 and 275/40-18 combo was the best setup I used

 

Appreciate the feedback, one and all. I took it to heart and opted for the 275/40/18s. Once I get them mounted/balanced, I'll post some pics.

 

Monkey wrench that **** and get 265/35 front and 285/35 rear