r u sure the 18 size were 245-40-18? i thought the oem option was 225-40-18

pirelli pzeros are ok, they're getting old. you should try the bridgestone s-03 (or s-02) or the michelin pilot sport. kuhmos and sumitomos and yokohamas are cheaper alternatives, and they are decent, but won't give u that edge. and i'm gonna assume u don't need a/s tires for snow, cause u've got pzeros, then don't go for the all-season ones like p7000. if fact, the max/ultra high performance tires provide better wet handling than do all-season tires. all seasons are compromised for low temp use like in light snow/ice. u can visit tirerack.com or tires.com for more lists.