most 17s generally because of the lower profile tyres sit the same and have similar or the same rolling radius
its just because when you put bigger wheels on it
emphaises the fact because you notice the big gap between the wheels and arches mores .
cheers, i have some nice alloys off my rover cabriolet and has the same offset/pcd so it'll save me some money
how much shall i lower it by, or will it look a bit spooney if i left it without lowering?