Dunlop has moved on from the Z1 to the Z2. I've had 5 sets of Z1 between two cars and it wasn't until the last two sets (purchased near the tire's end of life) did I have issues with them. So far, out of a total of 8 tires 6 have been defective in that there would be tears/cracks inside of the tire between the sidewall and the inner liner (casing?) which caused bumpy rides and excessive noise. Visually the tires would bubble out at the side wall as air filled in the cracked cavities. The problems occurred over the course of a year or so though with different mileage on the tires. It could be my fault though on two cars? One AWD subie and the other a 335. My bad for not purchasing the road hazard but i had burned through three sets and hadn't really had issues with them of this kind and the tires didn't last long enough for me to justify (in my mind) the road hazard. This is kind of too little too late but has made me somewhat weary of future purchases with Dunlop. It's somewhat not fair I understand but I had some really bad luck in this last run lol. I may try the Z2 someday but for now the Pilot Super Sports I'm using have been a greater tire for daily duties than the Z1. Maybe I lost some ultimate dry grip and the slightly softer sidewall gives me a hair less turn in response but it's not really much of a difference on the street.