求教前輪煞車碟正確尺寸 C30/S40/V50(D4/D4R)

C30 2.0NA 278mm
C30 D4 300mm
C30 D4R 300mm
-67kg

S40 2.0NA 278mm
S40 D4 300mm
S40 D4R 300mm?
-17kg

V50 2.0NA 300mm
V50 D4 320mm
V50 D4R 320mm
-0kg

C70 T5 320mm

煩請告知?部分

S40 D4 R版前輪煞車碟正確尺寸為何？320mm or 300mm?
S40 D4 R
https://picasaweb.google.com/PTHuang.popo/Volvo#5587520824093624002
https://picasaweb.google.com/PTHuang.popo/Volvo#5587520824316042578
V50 D4 R
https://picasaweb.google.com/PTHuang.popo/Volvo#5587522304780774898
https://picasaweb.google.com/PTHuang.popo/Volvo#5587524967585494290
https://picasaweb.google.com/PTHuang.popo/Volvo#5587524972771895538
https://picasaweb.google.com/PTHuang.popo/Volvo#5560158954965091666
https://picasaweb.google.com/PTHuang.popo/Volvo#5560158965414352562
但是這S40 D4R很怪，令人不敢買
https://picasaweb.google.com/PTHuang.popo/Volvo#5587310745565609426
https://picasaweb.google.com/PTHuang.popo/Volvo#5587310583938610466
https://picasaweb.google.com/PTHuang.popo/Volvo#5587310563355960802


在原廠技術規格裡用的單位是"吋",剛剛問過保養廠,回答是15,16,16.5吋
15"跟16"跟16.5"這應該是包含卡鉗的尺寸,T5碟盤前12.6",後11",2.0NA碟盤前11.8",後11"

This sport brake system is available with four-piston brake callipers (326x30mm brake disc) or six-piston brake callipers (355x32mm brake disc).