1.以EU Lable來說:PS4和ER33的dB值差不多!但是PS4比較新!PS4 225/50R17 98Y XL C/A/71:https://www.michelin.co.uk/tyres/michelin-pilot-sport-4ER33 225/50R17 98Y XL E/C/71 :http://www.bridgestone.co.uk/car-tyres/tyre-catalogue/2."左右彈跳感"通常來自於後防傾桿(雙A臂或多連桿)遇不平的路面,拉扯兩邊的懸吊系統所造成的,基本上換"細"一點的可能有解!