I have a 2013 X5 35i Xdrive Platinum Metalic Grey which came with a stock 18" wheels and Bridgestone RFT tires(I'll switch for winter). I've been looking to switch to 215 21"wheels - ferric (for summer) and I've researched for tire availability and cost $2,600+ front and rear (Dunlops or Pirellis are the only option). The 215's ferric wheels set up on X5's looks so nice. What I'm not reading is, 1. how long does this tires last (10Kmiles?), 2. How bad is the road noise (can not hear radio, cabin noise or phone talk?), 3. How does it feel on highways (sensitive on ruts etc.) and regular streets (avoid potholes to avoid denting the wheels, etc. ). I value any opinions and help me decide before I dive in on 215's (21") ferrics ..
Thanks.