Another tyre question.

Needed some new front boots and my friendly local tyre supplier is the PCGB RO who also has a 996 so went with his recommendation - Kumho Ecsta PS91s. So far so good, now I'll be replacing the rear Bridgestones when I get back from the Ring in May so asked for a price on the rears. Problem is that he has a 996.1 running 265/35r18 and mine is a 996.2 that has a 285/30r18 - they don't make the PS91 in the 285/30r18 size I wouldn't have put them on the front if I'd known that they didn't do them in the right size for the rear. So, should I: A: Put the PS91 265/35r18 on the back and forget about it B: Put a different brand on the rear in 285/30r18 and forget about it C: Not sleep at night until I've changed all 4 to factory sizes and matching brands. D: What they're not N-spec, are you a madman????

E: Seek advice from the person who talked you into the situation in the first place. :wink:

+1

Hi Eldavo. This comment will not necessarily be what you want to hear but I had Kumho Ecstas on my C4S which were hardly used. Upon close inspection they had developed very fine cracks to the side walls and the N/S/R was slowly loosing pressure. The 2 rears were shocking considering the lack of use and deep tyre tread remaining. This is just my experience and I am not saying the same will apply to others but I changed to Michelin PS2's all-round which I have to say I am very happy with by comparison (even though they are 'old tyre technology') the rubber compound of the PS2's is noticeably better. IMHO I would change for all 4 matching, perhaps the supplier will credit the other 2 and do a deal with you?

How old were they though? That's probably biggest factor on tyres cracking. What size rear wheels do you have? I run 265/35/18's and there fine with no complaints. Thing is if you do swap out the front there such a common size used on a lot of cars that someone will buy them.

Ive put a couple of hundred miles on the fronts and they're great - also got them at a VERY favourable price so wouldn't put this back on the supplier, especially as he's a friend. To be fair, he asked me what the sizes I had were and my reply was 'the same as yours" so it's my fault for not checking first.

I would prefer to have factory tyre sizes all round and matching make / model. I run Kumho Ecsta KU39 and love 'em, but mine are 265 rear on a 996.1. I'm thinking of ps91 next time as a peg up - the ps91 has been designed with the 911 in mind. If I were you though I would bet 4 matching tyres in factory size and punt the ps91 fronts on eBay, should be easy to sell and send using parcel2go. In fact I would have them off you but my fronts aren't running low yet.

Morning Stormy, had your car done a lot of sitting around? As sitting can do more damage to sidewalls than use does. Kumho make really good tyres. They were "just another budget" when they first became known over here but thanks to supporting lots of one make racing championships, they grew their market share rapidly. No denying PS2s are great tyres but Kumhos cracking certainly isn't the norm. I've run them for years on my every day cars. I currently have 4 matching KU39s on my old Volvo estate. I fitted them at 155k and it's now on 182k, so 27k miles. The rears are still fine but the fronts are getting low. No cracking though and they grip and grip. Fronts let go in the wet a bit earlier than they did which is to be expected. 9.6 out of 10 owner reviews too. Wouldn't be that high if they cracked for everyone. Eldavo I'd do as above and speak to the guy that got you them. Worst case then 265s on the back is no big deal, as per the 996.1. They can look a bit undersized though. It's either that or replace all 4. Bummer. ETA. Yes do Wasz suggestion. Get half your money back and start again.

Less than 4 years old & sub 6k miles when the cracks became apparent. Rears are/were the standard recommended size for my model which is 295/30/18 (different size to OP). My point really was about the quality and I know people will dispute this no-end and I am defo not a tyre snob but the rubber compound appears to be of a completely different quality with the PS2's. I suppose in short my answer to the OP's question is C!

Hi Marky. Yes maybe the sitting around I give you that and I am not dissing Kumho as a brand, certainly not of budget quality anymore but the replacement tyres look a much better quality all-round and therefore I was just pointing this out to the OP as he is questioning his tyre decision. I would not expect that sort of cracking to the side walls and perhaps at the rear is due to the weight across the rear axle, my C4S is kept garaged by me and was kept garaged by the previous owner so time will tell I suppose as my usage will continue by the same/similar miles per annum :thumb:

97-98 MY (C2) cars had 265-35-18 rear tyres & 99-04 C2 & C4 models had 285-30-18 tyres on the same size wheels. I'd not see a problem with fitting the larger size tyres to the rear wheels so that you have the same type of tyre all-round. With regards tyre storage/degradation, it's best to keep the car off the concrete, something like carpet or foam tiles under the tyres will help stave-off cracking.

B. A good tyre is a good tyre. Really doesn't matter who makes it (or at the other end).

Comment in Adrian Streather's 996 essential companion: "Caution- The wheelarch area must be reworked on pre-model year 2002 narrow body 996s if 285/30 and 295/30 R18 tyres are installed." I'm sure he means 'or' rather than 'and' but apart from my pedantry, he does tend to know what he is talking about.

It's a 996.2 2002, no rubbing issues with M030 and 285s on 10J 'GT3" BBS wheels. In fact, looking at slight (7/15mm) spacers.