Correct Tyres Sizes for Sport Design 18s

[stevett]

I have SportDesign 2 piece BBS 18 wheels on my C4, but noticed front tyres are 225/40/18 and rears 265/35/18.

Given that is nearly time for a tyre change, should i actually be fitting 285s or even 295s and if so are these lower profile 30 tyres more susceptable to pot hole damage than the slightly less 35s as I seem to be hitting a fair few at the moment and so far no probs with 265/35s (touch wood)?

I am also curious whether the friction/mpg is actually that noticable from 265 to 295. Obviously 295s costs a lot more to start with....

And finally, I know similar questions have been asked, but I was specifically informed by a local tyre dealer that the compound/tread patten on a Michelin Pilot Sport 2 N3 tyres mean they wear significantly less and lasts a fair bit longer than Michelin Pilot Sport N1. Is this the case and is there any benefit from moving to N3s as they looked to not have directional treat of N1?

Thanks, Steve

 

[minny]

The Michelin Pilot Sports are directional tyres and the Pilot Sport 2s are assymetrical. Just to add to the complication, if you look at web photos of the original Pilot Sports, the tread design was the arrow shaped. However, when it moved from N0 to N1 the shape of the tread for Porsche N1 Pilot Sports was different from the regular non N-rated ones. In America these were known as Pilot Sport Rib. Although still directional the tread pattern is completely different and more similar to the new Pilot Sport 2. Google each one so that you can compare them.
Ideally you should keep the brand, tyre model and N code the same on all 4 tyres.
I've always used Continental Sport Contact 2 s which I like a lot but found the wear rate on the rear tyres rather significant. I've checked the alignment and all is in order but I still only got 5k miles on the rears. The fronts still have 6mm of tread! When I came to replace them last month I was offered Michelin Pilot Sport N1s for the same money so I took them and now have Michelins on the rears and Continentals on the front. The car does understeer slightly more but not enough to concern me.
i can't comment about the sizes as I also have 265s on the rears which are what is recommended for my car. Interesting thing is that the Continentals definitely offer more rim protection than the Michelin which looks like its slightly too small for my rim even though all specs are as per recommended for my model.

 

[minny]

Here is a picture of the Michelin Pilot Sport as it was originally when N0 and still is for non N-rated tyres:

Picture of the Pilot Sport N1 (or N2 for 17 inch tyres):

Picture of Pilot Sport 2 for both N and non N-rated tyres:

 

[Richard_Hamilton]

The pre-facelift 996s with 18" wheels were fitted with 7.5" wide front wheels and 10" wide rears. Tyre sizes were 225/40-ZR-18 front and 265/35-ZR-18 rear. When they brought out the facelift car they increase the front wheel width to 8", leaving 225/40s on the front, but fitting 285/30 rears. The 295s were only fitted to the C4S and Turbo, which have 11" wide rears.

Fitting 285s to the rear should be OK, and give a bit better rim protection, but personally I wouldn't fit 295s, as you might upset the balance and have more understeer.

Bear in mind that you would be fitting non-standard tyres, and a clued-up, over-zealous, insurance assessor might take exception to it in the event of an accident. Highly unlikely, but possible.

 

[Steveb]

I am also just about to change my Tyres, i have recently purchased some 18 inch split rims and currently have 225/40/ZR18s Front and 265/35/18 rear...the fronts are not to bad but the rears only have about 1k left on them, any advice appreciated into make and size
I have a 1998 996 C2

Cheers

Steve