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Thread: RS tires sizes and options

  1. #1
    Senior Member tcsracing1's Avatar
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    RS tires sizes and options

    I have a 1972 that was converted to "RS" with 15x7 fronts and 15x8 rear.

    I want period look tires but would entertain a wider tire on back.

    Avon looks to be period. Anyother options?

    Stock size should be 185 front 215 rear.

    Anybody stuff a 225 on the back?
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  2. #2
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    225’s fit easily on the back, but finding 15’s in a 225 is tough. Pirelli recently released cn36’s to fit 15’s
    Last edited by blucille; 12-24-2018 at 12:39 PM.
    found my hotrod motor, close enough, but still looking for 2.4 case 6121622 72 911t

    Alle deutsch

  3. #3
    Senior Member Arne's Avatar
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    Pirelli CN36 are available in both of the factory sizes, 185/70 and 215/60.
    In transit - 1972 911T coupe, born (and someday will be again) Silver
    Sold - 1984 911 Carrera coupe, Chiffon white; 1973 914 2.0, Saturn Yellow; 1984 944, Silver Metallic

  4. #4
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    Ed recommends Eagle GT for a lower cost option. That would use a 195/65 at the front and stay with the 215/60 rear.
    You really don't need more tire.
    I think the P6000 comes in the original sizing too, a little less than the CN36
    David

    '73 S Targa #0830 2.7 MFI rebuilt to RS specs

  5. #5
    Senior Member Arne's Avatar
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    P6000 doesn't look period, and the Goodyear is NLA in 215/60-15 now. For period looks, it's either the CN36 or Avon. CN36 is what RS's came with from the factory.

    For lower cost without dropping to a "touring" tire, Sumitomo has the 195/65 and 215/60 sizes in the H-rated HTR A/S PO2. But it doesn't look period either.
    In transit - 1972 911T coupe, born (and someday will be again) Silver
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  6. #6
    Senior Member Haasman's Avatar
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    The Michelin XWX are being remade again. The first series had issues on side wall belting count, but now supposedly all good.

    Coker in the USA and Longfellow Tires in England sell them.
    Haasman

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  7. #7
    Senior Member Arne's Avatar
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    But the XWX has never been available in the rear 215/60 size. Or any aspect ratio other than 70, for that matter. Period looking choice for 185/70-15, yes. Not much help for RS fitments.
    In transit - 1972 911T coupe, born (and someday will be again) Silver
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  8. #8
    Senior Member tcsracing1's Avatar
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    i have seen a backdate with AVON 185 fron 225 rear.
    Wondering if i should attempt the same.
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  9. #9
    Hi

    The options are on here https://www.longstonetyres.co.uk/cla...11.html#page=1

    The P6000 and Goodyear are not suitable tyres for a car of that period. It isn't that they don't look right. it is that they have the wrong carcass design. the Avon CR6ZZ, Pirelli CN36 or Michelin XWX are the only tyres with suitable carcass design.

    https://www.longstonetyres.co.uk/vin...von-cr6zz.html brilliant tyre. they don't look right, because they are not a period tread pattern, and they are a bit racey. but they are great to drive on in a car like yours.

    https://www.longstonetyres.co.uk/mic...tyres/xwx.html can't knock it. Great tyre, looks great, was OE. the only slight problem is that they don't do the wider rear.

    https://www.longstonetyres.co.uk/pir...rato-cn36.html whaat could be better. genuine period W rated tyre. perfect carcass structure. The back to back tyre tests for classic tyres give this incredibly high results. (check the link to the 911 page above). What more could you ask for. Porsche fitted it to these cars in period. Pirelli remade some, Posrche got involved with Pirelli and did their own testing and gave Pirelli the N4 Porsche Homologation so here we are 46 years down the line and Porsche are again recommending this Cinturato CN36 tyre for their cars. because it has the right carcass structure for these cars and it is built to modern quality control standards with modern compounds.

    Modern tyres do not drive as well on old cars as tyres that were designed to suit that kind of suspension and steering. so a P6000 may be better for the post 85 SC 911 but it is not as good on your car as the CN36 (unless you have modified the camber caster and suspension)

    image.jpg

    Oo that does read a bit like an advert doesn't it? But there you have it. of course you will make up your own mind. not just believe what me and Porsche are telling you.

  10. #10
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    Hi Dougal

    Seen that old ad before. Do you know the reason for Roadstar name rather than just Cinturato CN36 as per original factory fit to earliest RS?

    Steve

    PS I attended a Pirelli tyre clinic with Porsche Club and despite not being the sponsoring host tyre depot (or even present) Dougal/Longstone got a strong mention from the guy who I understand runs the Pirelli "quality control and depot inspection / ranking programme" in UK. Particularity when I asked his advice about a source and fitting Pirelli tyres for classic Porsche, rather than newer Porsche cars. I don't know Dougal -- from what I hear he is not shy and retiring type and maybe doesn't need any recognition from me -- nevertheless it seems from Pirelli official representative comments at that formal event Porsche owners owe Dougal a thanks for his central active role in getting / keeping these CN36 tyres available to us today as an option for classic 911. (No affiliation and no personal experience of Longstone just sharing info I picked up from Pirelli about Porsche Pirelli tyre approved tyres and programme in UK. Not explicit but impression I got from the exchange is without Dougal/Longstone involvement we might not have these CN36 available to us these days; if so contribution to availability of original and approved consumable is appreciated!)
    Last edited by 911MRP; 01-15-2019 at 07:11 AM.

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