Will it still need to be lowered with bigger wheels?

i have a 1996 audi a4 with the standard 15inch alloy wheels, im going to buy some 17inch alloy wheels with tyres fot it. The gap at the moment between the wheels and the arch is huge! when putting bigger wheels on does it cover the gap between the arch or will i still need to get some lowering springs to lower it down? please help!