winter tyres for a C4S 991.2 - issue of width

[GeorgeK]

Hi all,
I am looking to get some winters for my 991.2 C4S but would appreciate some help with the issue of width. Looking at the Porsche website and my user book, the recommended rear rims are 11J x 20 (I cannot use 19'') for 295/30 R20 tyres. The Michelin tyre configurator also comes up with the same answer: 295s for winter tyres. Yet 305s winters are available from Michelin with all the sizes identical to my summer tyres.

My question therefore is: can you simply substitute your summer tyres with winter tyres of the exact same dimensions or are there any mechanical/size issues that would cause problems if using 305 mm width winter tyres?

Many thanks for any help on this!

George

[GeorgeK]

Thanks for all your replies. In the meantime, I have done some more homework on the issue, and it turns out that, legally, I can only run 295 mm width winter tyres. At least this is specified under the Italian specifications for my car model.
My local tyre specialist states that I can use 295 mm width tyres on the same 11.5J x 20 rims that currently have my 305 mm summer tyres, and this has been confirmed in some posts that I have seen on the internet. Is this a commonly accepted view?

Thanks

George

[GeorgeK]

Thanks for all your replies. This has been most helpful
Michelin Pilot Alpin 4 are on order