Hi, I have a 2008 Ford Territory Turbo with genuine 18x7.5 with 36.6ET offset wheels with 235/55/18 tyres. I would like to put on 20" wheels with 275/40/20 tyres but I'm not sure on the width and correct offset of the 20" wheel I need. I like to have the 20" wheels close to the brakes where possible and not protrude the front wheel arches/guards. Appreciate it if anyone has any advise. Thanks.