both crossfires i have need new rear tires, i am thinking about getting 255/35 19 Bridgestone potenza runflats with 80% tread left for my limited xfire and micheline ps2 285/35 19 with 65% tread left for my srt6 coupe....all 4 for 140 plus 40 to get all 4 installed and balanced, should i grab it? i think so