305/30 R20 téli gumi átmérője: 691 mm.

A 305/30 R20 váltóméretei (téli)

14 col: 205/ R14, 215/ R14

15 col: 195/80 R15, 215/70 R15, 225/70 R15

16 col: 175/80 R16, 185/75 R16, 195/75 R16, 205/70 R16, 215/65 R16, 225/65 R16, 235/60 R16

17 col: 215/60 R17, 235/55 R17, 245/55 R17

18 col: 215/55 R18, 225/50 R18, 235/50 R18, 255/45 R18, 265/45 R18

19 col: 155/70 R19, 205/50 R19, 225/45 R19, 235/45 R19, 255/40 R19, 265/40 R19, 285/35 R19, 295/35 R19, 305/35 R19

20 col: 255/35 R20, 265/35 R20, 275/35 R20, 295/30 R20

21 col: 275/30 R21