Checking your owner’s manual allows you to identify the original tyres that Porsche recommends. If your tyre sizes don’t match the manual they may still be fit for purpose, however we do have a surprising large number of customers with classic Porsches coming into the workshop with incorrect fronts and/or rear tyre sizes.
If you or a previous owner of your Porsche has replaced the original tyres with aftermarket tyres, here are two good references that should help identify the original tyre size, and a range of alternative tyre size options. The first resource is an Official Porsche publication detailing tyre recommendation for classic Porsches Classic_recommended_tyres-2, and the second is a link to Michelin website that specifies by Porsche model the recommended tyres offered by this brand https://www.michelin.com.au/auto/manufacturers/porsche. When in doubt we recommend you check tyre sizes directly with Porsche, which is what we do at NINEAUTO for older or unique model Porsches.
If you’re not familiar with tyre sizes here’s an explanation of what each of the numbers relate to. The first tyre size numbers gives you the width of the tyre from sidewall to sidewall in millimetres. The second identifies the aspect ratio, i.e. the height of the tyre as a percentage of the width. So for the illustration above, the tyre is 50% of the 225 millimetre width, or 112.5 millimetres in height. The third number is the diameter of the tyre in inches, which is also the diameter of the rim.
If you have any questions regarding the best tyres for your Porsche please give us a call.