you ball joints and wheel bearings will wear quicker thats it really.
just make sur eyou get em checked regularly, then you wont fail the mot on what is essentially a cheap part
my cars bein on a mixture of 17s and 18s from new and its 7 years old now.
It literally left the dealer forcourt, and went to the localwheel shop for some 18s thatvery day, or so the service history suggests
as if 18s withtyres were £1700 back in 1999 lol