Many customers I speak with are surprised to learn their BMW, MINI or Mercedes tires are performance summer run-flats. When beginning to shop for tires the customer and I will address issues they disliked about their previous tires and many will explain that their run-flats did not perform well in the snow and ice. Many don't understand that the tires were intended for summer use only.
Summer tires are dramatically different in construction and rubber compound. The rubber compound is optimized for operating in temperatures above 40 degrees Fahrenheit and has no siping in the tread blocks to provide a more stable foot print for quicker steering response and better handling. In colder temperatures, the summer tire's rubber compound will become hard and more plastic like. It can even be damaged because the tire becomes too brittle from the colder environment.
An all-season tire has a rubber compound designed to stay more pliable in a wider range of temperatures. The tire will be softer in winter weather, which will allow it to conform to the road and handle better when the temperature begins to drop. In addition, the all-season tire has siping to allow the tread blocks to flex, which creates hundreds of more bitting edges for snow and ice traction.
 Bridgestone Potenza RE960AS Pole Position RFT |
 Michelin Pilot Sport A/S Plus ZP |
 Yokohama AVID ENVigor ZPS |
 Pirelli P Zero Nero All Season Run Flat |
If you're looking to replace your current run-flat summer tires with another run-flat that has good capabilities in the snow, ice and winter weather, I would recommend the Bridgestone Potenza RE960AS Pole Position RFT, Michelin Pilot Sport A/S Plus ZP, Yokohama AVID ENVigor ZPS or Pirelli P Zero Nero All Season Run Flat. All four of these options had great success as a non-run-flat version, therefore the manufacturers decided to turn their successful performance oriented all-season tires into a run-flat offering to cover the emerging need.
To see if any of these snow and ice capable run-flat tires are offered for your car, shop by vehicle. You can also use the sort tab in the left-hand column to only show run-flat tires.
Here is a Link to the tire:
http://www.tirerack.com/tires/tires.jsp?tireMake=Pirelli&tireModel=Winter+Carving+Edge&partnum=36TR8WCEXL&vehicleSearch=false&fromCompare1=yes&wtpackage=true&affiliate=WC3
There is no general rule of thumb for which is better but buying wheels and tires give you versatility of changing out winter and summer tires at your leisure from your own home. The wheel tire package usually has more upfront cost but once you factor in a few years of mount and balance fees the price ends up being pretty close to the same. Just 245/40R18 run-flat winter tires start out at $852 for the set before shipping. If you did wheels and tires together you could have run-flat winter tires installed on alloy wheels starting at $944 for the set before shipping. Please give me a call or email if you need more specific assistance.
Zig
Thanks!
Thanks!
http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE960AS+Pole+Position+RFT&partnum=055HR6RE960PPRFT&vehicleSearch=true&fromCompare1=yes&autoMake=BMW&autoYear=2010&autoModel=328i xDriveSedan&autoModClar=BaseModel&affiliate=WC3
http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE960AS+Pole+Position+RFT&partnum=055HR6RE960PPRFT&vehicleSearch=true&fromCompare1=yes&autoMake=BMW&autoYear=2010&autoModel=328i xDriveSedan&autoModClar=BaseModel&affiliate=WC3