Size does matter apparently

Those tire sizes will not affect the ABS/ASR since they are close (+3.2%) to OEM front to rear differential (+4.1%), but the tires are ~1" smaller in diameter than OEM, which effectively lowers her by ~1/2" or 12-13 mm. Combined with what you have already done, she may be a low rider with insufficient ground clearance. If so, you can always raise her back up to CS standards, which would probably be a good idea.

The speedo error will be 4.1%.

 

Curious as to why P Zeros? I had them on my 911 and they were like bricks. Switched to Michelin Pilot Super Sports. Much better tire in every respect, IMHO, and highly regarded by many here.

 

I have a set of Challenge rims and was looking at running either 235/40 and 285/35
Or....245/40 with 295/35. The rims are .5 inch wider than the starfish 18's,
Seems like 245-295 would be great ...any issues with that ?

Other than front fender clearance, so have them rolled....

 

I have the Michelins and IMO a much better tire for every day use. I had PZeros on my Jag also and changed to Michelins. Less expensive too. Another bonus is that the Michelins protect the rims better than the Pirellis with light contact with the curb.
Alan

 

Would these sizes work with standard 360 wheels?
I always thought they'd look better with wider tyres. I'm going to change to pilot sports. Had a set on my gt3 and they were better tyres all round, and not that it matters, they were also more quiet on our rough chip roads.

 

I have 235/40/18 & 285/35/18 on standard 360 rims - not a problem, though that would be as far as I'd push the front. Rear can probably take a 295.

 

7,5x18" rims will accept up to 245 wide tyres, if the aspect ratio is 45.
7,5x18" rims will accept up to 225 wide tyres, if the aspect ratio is 40.
8,0x18" rims will accept up to 255 wide tyres, if the aspect ratio is 45.
8,0x18" rims will accept up to 245 wide tyres, if the aspect ratio is 40.
10,0x18" rims will accept up to 305 wide tyres, if the aspect ratio is 40.
10,0x18" rims will accept up to 305 wide tyres, if the aspect ratio is 35.
10,5x18" rims will accept up to 315 wide tyres, if the aspect ratio is 40.
10,5x18" rims will accept up to 315 wide tyres, if the espect ratio is 35.

Can you squeeze wider tyres on than what is shown here? Yes, of course. Is it recommended to do so? No.

Note that these figures are NOT what will fit on the 360. It's a guideline to showcase which tyre widths are approved for a particular size of rim in relation to the tyre aspect ratios being discussed here.

 

Easiest thing to do if there are questions on wheel width vs tire size is to look it up on TireRack's specs section on the tire you want. Those are the manufacturers' recommendations.

Does not help on whether it will fit your Ferrari, of course.

 

Yes, and rolling diameters are listed also so compare that with OEM if you are worried about gearing or speedo accuracy...

 

Maybe just out of stock? I certainly have them in MPSS.