winter tyres for a C4S 991.2 - issue of width
winter tyres for a C4S 991.2 - issue of width
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Discussion

GeorgeK

Original Poster:

19 posts

229 months

Thursday 16th November 2017
quotequote all
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

Monch

713 posts

231 months

Thursday 16th November 2017
quotequote all
295 are the correct size tyres, they are N rated and can be used with chains

these are the ones to get...

MDL111

8,788 posts

205 months

Thursday 16th November 2017
quotequote all
I believe you can, don't see a reason why not - my winter tyres are also one size down from the summers, but I might consider going up a size at some point as it protects the rim a little better

MaxA

238 posts

172 months

Tuesday 21st November 2017
quotequote all
GeorgeK said:
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?
I would say yes, you can substitute and no, there are no mechanical issues at all with running identical sized winter and summers.

GeorgeK

Original Poster:

19 posts

229 months

Tuesday 21st November 2017
quotequote all
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

MDL111

8,788 posts

205 months

Tuesday 21st November 2017
quotequote all
GeorgeK said:
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
not a Porsche but I run summers and winters on the same rims (switching over tmrw actually) and as above both front and rear are one size down

MaxA

238 posts

172 months

Thursday 23rd November 2017
quotequote all
GeorgeK said:
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
If it helps, George, I'm running 295/30-19 Nokian Hakkapeliitta7s on my 11.5x19 OEM rims right now.

Dr S

5,134 posts

254 months

Thursday 23rd November 2017
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I also had to buy slimmer wheels for Winters on my 7.2 GT3. Not sure whether that is driven by Porsche or the tyre manufacturers

TonyG2003

258 posts

120 months

Thursday 23rd November 2017
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My winters are 295mm on 19 inch wheels which were supplied directly from Porsche as to opposed to the 20inch on my summers.

GeorgeK

Original Poster:

19 posts

229 months

Sunday 26th November 2017
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Thanks for all your replies. This has been most helpful smile
Michelin Pilot Alpin 4 are on order lick