997.1 Carrera S 19" Sport Design Tyre Query

[R60BBA]

Folks,

Need to replace the rubber on the motor ahead of the upcoming Ministry of Transport test and am currently assessing my tyre options.

Car is a 997.1 Carrera S with factory 19" Sport Design wheels (option code: I407).

Rim sizes
Fronts: 8J x 19 ET57 (pn: 99736215604 x2)
Rears: 11J x 19 ET67 (pn: 99736216207 x2)

Tyre sizes
Fronts: 235/35/19
Rears: 295/30/19 or 305/30/19???

The car is currently wearing 235/35/19 + 295/30/19 Falkens (fitted by the previous owner). Will be putting 235/35/19 rubber on the fronts however I am unclear on what size I should fit on the rear.

There is debate online on whether one should run a 295 or a 305 in the rear (for various reasons I won't delve into). However, I would like to know what rear size tyres Porsche fitted my car with from factory. Ie what is the factory specified tyre size for 997.1 Carrera S 11J rear Sport Design wheels? Is it 295/30/19 or 305/30/19?

Note, will be going Michelins but currently undecided on whether to go for N rated PS2s or non-rated PS4Ss (cannot seem to find N rated PS4Ss in 997 tyre sizes). I actually wanted to give the Goodyear Eagle F1 SuperSports a try, as have been running Michelin PS4S on my other car since they came out and fancied a change, however unfortunately Goodyear do not produce them in the rear sizes...

 

[Tyremanrob]

To answer your question I believe but am perfectly happy to be proven wrong is that if your car is a C2S then it would come on a 295/30R19 rear fitment and if it's a C4S then it would come on a 305/30R19 fitment from new.

The reality is however that 10mm difference in section width spread equally over a central line equates to 5mm each side which is quite frankly irrelevant.

Tyre manufacturers conform to ETRTO specifications which allows for variation in production tolerances and therefore certain brands will be bigger or smaller than their competitors anyway even if they are technically the same size.

You can happily fit either and Goodyear make the excellent Supersport R in both 235/35R19 & 305/30R19, I can highly recommend them :thumb:

 

[Tyremanrob]

To answer your question I believe but am perfectly happy to be proven wrong is that if your car is a C2S then it would come on a 295/30R19 rear fitment and if it's a C4S then it would come on a 305/30R19 fitment from new.

The reality is however that 10mm difference in section width spread equally over a central line equates to 5mm each side which is quite frankly irrelevant.

Tyre manufacturers conform to ETRTO specifications which allows for variation in production tolerances and therefore certain brands will be bigger or smaller than their competitors anyway even if they are technically the same size.

You can happily fit either and Goodyear make the excellent Supersport R in both 235/35R19 & 305/30R19, I can highly recommend them :thumb:

 

[R60BBA]

Thanks for your response Tyremanrob and agreed on the C2S vs C4S comment however I have read online that C2S with Sport Design wheels came with 305 rears (but only seen this confirmed for gen 2s, haven't read anything concrete for the gen 1).

So am still after a concrete answer.

With regards to the Goodyear SuperSport R, I did notice that they are made in the aforementioned sizes, however they are more of a track focussed / Cup 2 equivalent tyre. I am after a road tyre (this car will not really see track, perhaps a lap of the Ring but that's about it) so the SuperSport R isn't quite what I am looking for!

 

[spinnaker]

As far as I am aware the supplied C2S rear rims are 295 wide, but people do tend to be happy enough to put 305 tyres on them. Not sure how you confirm it other than to speak to someone at Porsche.

People tend to go for N rated tyres when they are still in a Porsche warranty but almost everyone rates the PS4S tyres as being much better than PS2 tyres. I plan on switching from PS2 to PS4S in the next 3-4 months despite them not being N rated.

Michelin have just announced they PSS5 tyre a few weeks ago but not yet in 997 sizes. No reviews that I have seen so far and probably not going to be much help if the MOT date is near.

 

[R60BBA]

Yes another problem, would like to also try the new PSS5 but they are only currently available to OEMs and are not yet on general sale, and doubt they will be in time for the MOT.

It did cross my mind to take this up with Porsche whilst writing my original post but thought someone on here may know the answer. Will also take up with them and revert though.

 

[spinnaker]

Agreed, I did a quick search earlier and couldn't see any sites that handily match up rim sizes with recommended tyre sizes.

I was about to buy a full set of PS4S tyres for mine a few weeks back but decided to wait another few months to see what the deal is with the PSS5 tyres. The PS4S is probably the way to go as there will be no long term reviews of the PSS5 tyres talking about the rate of tyre wear for months and months. The PS4S seems to be the happy medium.

 

[R60BBA]

Okay so quick update.

Spoke with Tony Suckling, Service Manager at Porsche West London who suggested checking the label on the door shut and the drivers manual for confirmation.

Checked the label on the door shut which listed various tyre sizes and tyre pressures and so wasn't particularly helpful in resolving my query.



However, I then proceeded to the manual, of which page 247 outlines the wheel and tyre options for the Carrera and Carrera S, confirming:

11J wheels = 295/30/19 sized tyres
11.5J wheels = 305/30/19 sized tyres

The Carrera S 19" Sport Design rear wheels for the 997.1 Carrera S are 11J, thus 295/30/19 is the Porsche recommended tyre size.

Interestingly the manual suggests that the Carrera 4 and Carrera 4S should run 305/30/19 sized tyres on 19" 11J wheels...

Anywho, glad I got to the bottom of this and will be going to the tyre shop to fit fresh rubber (Michelin Pilot Sport 4S - 235/35/19 and 295/30/19) on all four corners later this afternoon.

Cheers

 

[Magic919]

That all matches my understanding. I changed to Carrera Sport wheels and fitted 305s on my C2S to match the 11.5 rear rim.

 

[Svvg]

Hi R60BBA (I think you’re on the M3 Cutters Site - and we’ll have messaged over the years….). I have ps4s on my M3 and they are excellent - but have 6 year old ps2 N2 rated on our 997.2 carrera s.

I’m reviewing how essential the N2 tyre rating is - and stumbled across this thread. How did you get on in the end - did you fit the PS4s?

 

[911UK]

295/30/19 always what's on the manual

 

[Svvg]

Thanks - Noted on sizing, but I was after feedback on the ps4s vs ps2 N rated. Presumably N rated isn’t the be all and end all - particularly if you’re no longer within warranty?