Winter tyres tyre width 225 mm tyre cross section 55 rim diameter 17 inch load index 97 up to 730 kg speed rating h up to 130 mph installation all round tyre rolling resistance e wet grip e noise emission 68 db noise classification nc 1 runflat sipe asymmetrical tread runflat identification dsst dunlop rsc bmw run flat technologies dsst dunlop self supporting technology rsc runflat system component erstausrstung bmw