- 205 = Tyre width = 205mm - 45 & 50 = Profile = This is the sidewall height of the tyre e.g 45% and 50% respecitively of 205mm - R16 = Rim size = 16 inches. So diff is in the profile. A lower profile can provide more steering accuracy and grip however may compromise ride comfort. Lower profile IMO looks better though. A lower profile generally results in higher prices too. Hope that helps