Tyres (again)

Hi I recently posted a query about the rear 19" tyres on my 1998 996 C2 and the excessive wear. Clearly I am going to have to get them all set up properly as the wear is not even. In looking for replacements I have found that although the fronts at 235/35/19 match the same rolling circumference of what would have been an original 265/40/18 the rears at 265/35/19 are larger by about an inch in diameter (the speedo stlil reads okay). To bring it down to the correct size I would have to get 265/30/19 tyres and although they are available I cannot find any N rated tyres in the size. What do people think - is it acceptable to run the larger tyres? Perhaps this is contributing to the strange wear I am having? Or should I just go for a good brand non N rated tyre of the smaller size? Seems strange that with all the 19" wheels around I cannot get an N rated tyre! I would like to just change them all for the original sized 18" but that is an expensive way to go and I do like the look of the wheels I have at present. I'm tempted to go for a couple of Falkens on the back (leaving PZeros on the front) and see how they wear as then at least I won't be losing as much money if they wear out quickly. Any comments gratefully received. Thanks

My tuppence? If you are using 19" wheels, why are you considering N-rating? 19" were never fitted to 996s, so if you are running non-standard wheels, why not use non-standard tyres? There, 3 questions in a row! Seriously though, I ran non-Ns on my 996T (albeit standard wheels) and found them to be absolutely fine. I did check that my insurance company were happy about it first though. I doubt if the uneven wear is due to them being 19". Much more likely that the alignment is out.

Thanks Richard. I hadn't really thought about not bothering with N rated tyres if they weren't standard anyway. Any thoughts on whether it would be beneficial not to have the present circumference size being larger than standard and the fronts? Dropping down to 30 profiles means an inch overall less diameter and less air between the road and the rim. The ride isn't brilliant over potholes as it is. And I'll be back to square one over deciding on tyre pressures - no idea what I would have to have them at!

Personally, I wouldn't use 19's, but if I didn't have the option, I would want the diameters to be the same as a standard set of wheels & tyres. Having larger rears, you will have a slightly nose-down attitude. (Not as bad as nose-up though). I understand you dilemma though - lower profile tyres will give you a harsher ride. I don't think there is an easy answer.

Sorry to climb on the back of your post Steve, but I am needing to replace the 2 rear tyres on my car (295/30 ZR 18 N3) - the best price I can find for Michelin Pilot Sports is at My Tyres for £237.94 each - anyone got any better ideas ? What do folks think about home fitting ? - the car is asleep at the moment without MOT or tax ! Chris

Blackcircles or camskill?

Thanks Chris - Camskill seems to be cheaper (£215.40) - Blackcircles more expensive.

With an inch larger diameter I suppose the car is only half an inch higher off the ground at the back and it's not noticeable but I would like to get it back to how it was designed. I have toyed with the idea of changing all the wheels back to 18" but it gets a bit expensive. I really don't want to get any more Pzeros as although I know the wheels probably need proper alignment the rate at which they wore out was horrific and I've seen bad reviews about their wear rates from others. I was thinking of trying some Falken 452/453 tyres as they are about £70- £80 cheaper each but are described by my local supplier as still being one of the top cheaper brands. Has anyone any experience of them?

I just put 265/40/18 and 265/35/19 into a tyre size comparison calculator and it says both diameters are exactly the same at 26.3" The 265/30/19 is actually 1" smaller in diameter http://tire-size-conversion.com/tire-size-comparison/ Check out Oponeo for tyres. Just bought 305/30/19 N1 Bridgestones for mine - £232 each[ ]

Hi Alan. Was that fitted or was that extra to fit?

Thanks. Richard Hamilton's book shows the rears at 265/35/18 and I was working on that but I'll check my car handbook just in case it says different. Oponeo looks good, thanks. I'll start comparing all the prices.

That was the delivered price. Extra for fitting but my local charges £15 per tyre so still very reasonable at £247. Not sure what my PC would charge to fit?![ ]

They were 265/35/18 on the pre-facelift, and 285/30/18 on the facelift. See here: http://www.porscheclubgbforum.com/tm.asp?m=230744

Thanks Richard. By the way your book is very useful, I've already had the left rear light off and checked that the emergency release cable is in there and working - just in case! Being really anal about the tyres, 235/35/19 at the front makes them 25.5" dia instead of the 25.1" original. Changing the rear down to 265/30/19 makes them 25.3" which is the same size as original but then would be slightly smaller than the front. So it would be the opposite of the original being the smaller at front. Don't see anyway around this problem with sizes. Only very small difference and I suppose with tyre wear perhaps it doesn't matter too much. I've made the decision that in the longer term I will look out for some good 18" wheels (sports classic or GT3 type) and in the meantime put on some Falken 265/35/19 and get the alignment set up properly. Thanks to all for the suggestions.