I'd like to replace my Bridgestones with PSS. Also, as I have CL's I'm looking to fill the wheel opening with a slightly larger tire. If I could install spaces I would but can't with the CL's. I'm thinking about going from 305 & 235's to the 325 & 245 sizing. As my rear rims are 11" I'm at the narrow limit for the wheel with that tire size on the rear which will cause a slight bulge in the tire I suspect. It should also visually better fill the wheel opening at the same time. I'm wondering if anyone has mounted these size tires to stock width 19" rims and how it worked. Photo's would be great too. Thanks for any help provided

 

All the cars I know running this set up have larger width wheels front and rear.

Typically 8.75 to 9 inches at the front and 12 inch at the rear as per the GT3 RS 4.0 and GT2 RS.

Not sure if you can mount these on OEM size turbo wheels. Perhaps some vendors can chime in?

 

Thanks for your input. According to Tire Rack they're both within the range of acceptable rim widths, but I'm at the narrow end of that range. That's why I'm wondering if anyone has had some real world experience here. There's also the slight increase in tire height and change in stagger to consider. I'm assuming I'm OK here given the small difference and the fact that TT owners seem to, as you point out, put on these larger sizes, rim width wouldn't be a factor here.

 

There's a reason Porsche put wider wheels front and rear with the larger tyre size. I'd stick with what Porsche does in practice (wider wheels) rather than trusting tire track if you do any sort of performance driving at high speed.

There are no issues from a rolling diameter perspective as the 245 and 325 tyres are within Porsche's than less 3% variance guideline for the 4wd system.

I've done a few thousand miles including circa 100 laps of a very fast open track with no issues albeit I went with wider wheels as Porsche do for their GT3 RS 4.0, GT3 RS Gen 2 and GT2 RS.

 

I don't know if this will help at all but here goes:

1) I had those tire sizes but in 20in on my 997.2 C4S with no issues but my rims were 9in (ft) and 12in (rr)

2) When I owned an ISF it came with a 9.5 in rear wheel with a 255 tire...guys were following Tire Rack and putting 275/285 tires on the stock rim with no issues and if you pick the right tire it may not have bulge (they found that different tires had actual different widths) and for you if you want to stay with PSS they are usually the wider

Good luck and if you decide to try it definetly post pics...