The Pirelli P-Zero Nero M&S or the Michelin Pilot Sport AS? Need to replace the rears at 20K+ miles. Down to the wear bars.

Make sure all four tires match, which is more important than all other considerations.

Keeping the above in mind, these two tires have been nearly equal in dry grip as well as handling/cornering from our experience. The Pirelli has a significant price advantage in most sizes.<ul><li><a href="http://www.tirerack.com/a.jsp?a=AR8&amp;url=/tires/index.jsp">Tires</a></li></ul>