? for those running 245's on the front
 

Has the wider front tire made the steering effort noticeably heavier?

It looks like NISMO is showing a 245 front and 275 rear stagger with 8.5" and 9.5" wheels. This should increase the car's overall cornering ability but I'm wondering if it will diminish the nimble feeling that the car currently has. Any input from those already running this combination?

i have a 245 on the stock 17's. yes, it is "heavier." it feels as if some of the power steering is cut out. you notice it when the top of the steering wheel is at 2-3 o'clock. obviously, this is relative to the speed you are traveling.

Thanks for the info. I think part of that feeling in your set up may come from running the 245s on a relatively narrow 7.5" wheel width.

I'm trying to decide on the NISMO GT4s (8.5" wide front, 9.5" wide rear) with 245 and 275 tires. Using that set up, the wheel width is 88% of the tire width on both front and rear, which is close to ideal according to some sources.

Keep in mind that the 90% of tread width guideline is 90% of the tread width. This is not necessarily the same as the tire width (i.e. 245). You can find treadwiths for most tires on the TireRack site as well as most other tire sites.

For example:
A Bridgestone S-03 tire in 245/40YR18 has an actual tread width of 9" (Not the 9.64" designated by the "245")

This means the 8.5" wide front wheel is 94% of the treadwidth for these tires.

I'm running 245s in the front on the stock 17s, and I haven't noticed any difference in steering feel. I do notice the car tracks grooves and ruts in the pavement more, but I don't know if it is because of the width, the type of tire, or another issue. The 245s look better in the front than the stock setup, for sure.

I'm running the 245 front 275 rear combination.
Did not notice any steering effort increase. Did notice that the car tends to track road ruts a little more, but not a big deal. However, the car's balance feels much better. As soon as the break in is over, I'm sure that I will be testing the handling aspects more closely!

Good point. Don't some sites publish a tread width as measured on a specific wheel width (measured rim width)? This might make coming up with the 90% formula more difficult.

Yes, but I think as long as you stay in the tire's recommended wheel widths the change in tread width is probably negligable (spell check please).

245/255s
 

I'm trying to find ultra high performance all season tires for my Touring 5AT with 7.5"f and 8"r wheels. There are a couple of choices, stock size 225/50/17f and 235/50/17r. My only choice is the Michelin Pilot A/Ss for stock and 245/45/17f and 255/45/17r for a Sumitomo set of HTR+s.

My problem is the Sumitomos on the front have the 7.5" wide wheels as the minimum and the rear have to have 8" as the minimum width for each tire. This is true of all the choices I have and I'm not very comfortable w/them. Won't I get a big bulge at both ends of the car going with the 245s and 255s? I'm being cheap here, the Sumitomos are 50% the price of the Pilot A/Ss but I can't get them in the stock sizes.

I'm asking for advice, pros and cons on the stock vs. the larger tires. On the one hand, I would rather stay w/stock but, the larger tires are so much less money. However, I do not want to screw up my suspension geometry. Any thoughts?

Boomer

check out the KUMHO's in those sizes. somebody has pictures of those on stock whels on the site (maybe pistolpete)
You have your choice of two different types of Kumho's:
the 712 Ecsta's (ultra performance all-season),
or the Kumho MX (max-performance)

Thanks,I'll check them out.

I am running Kumho 712s in 245/45r17 and 255/45r17 sizes, using my stock enthusiast wheels. The tires fit well, and the car seems to offer better traction than before. I have some pics I took last weekend, I will post them tonight.

Kumho also makes the MX, and I believe the 711 in those sizes. There are other tires available in that matching size, check out tirerack.com and tires.com.

Here is a link to my original post, with a couple of pics of the new setup.

https://my350z.com/forum/showthread....threadid=11767

I am happy with my decision to go with the 712s in those sizes, especially considering it cost less than 450 bucks installed.

did you see the pics of my sumi's? very little buldge, if any.

https://my350z.com/forum/showthread....ighlight=a%2Fs