By and large Porsche is more frequently equipping new Boxsters with Bridgestone Potenza RE050A tires, cheaper to replace than the PS2's and longer tire life, as they have a stiffer sidewall which is really advantageous for the Boxster. I had the Michelins on my '06 and found that they were a good tire, but replaced them with Bridgestones. Fortunately my '08 with 19" wheels came with the Bridgestones, and enjoy the crisper turn in. You may wish to check the Bridgestone Pole Position tires, as they are rated even higher, but make sure they are suitable for your needs. Some reviews can be read at:
http://www.tirerack.com/survey/SurveyComments.jsp?additionalComments=Y&commentStatus=P&tireMake=Bridgestone&tireModel=Potenza+RE050A+Pole+Position
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