A friend is buying a 2017 mini convertable and was wondering what rim size it can take.
Also looking for black spoke rims if anyone has suggestions on some good prices and where to look.

 

Like many MINIs hardtop or convertible the standard wheel for the Cooper S is 16x6.5" with option for 17x7" or 18x7". As the rim is larger the tire sidewall gets smaller which makes for firm riding and less comfort.

15" wheels come with non runflat 175/65-15 for the base Cooper convertible
16" wheels come with 195/55-16 runflats but tire can be non runflat 205/55-16 for the Cooper S (also see 17" and 18")
17" wheels come with 205/45-17 runflats but tire is often replaced with non runflat 215/45-17
18" wheels come with 205/40-18 runflats but 215/40-18 non runflat can be used