Getting my wife an X3 and she wants some rims on it. I see some have gone 19" but what about 20"? What is the widest tire I can fit? I am thinking 275/40/20 is it possible? I had an '03 4.6is so I am familiar with that but I am curious as to what I can do with this. Thanks!!!

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'06 Porsche Cayenne Turbo S
Marine Blue/Sand on 22"s
'02 Porsche 996TT Ruf 550 Rturbo
Guards Red/Black
'04 X3 2.5i
Black/Black(Wife's) on X5 20's
'07 BMW 328xi Coupe
Crimson Red/Black (Wife's)