225x45x17 on front 17s

[thstone]

You can even fit a 235 on the stock front wheel (if the tire of your choice doesn't come in a 225).

Boxster race cars run with a set of rear wheels also on the front to get 255/40/17 on all four corners. But you'll need adjustable sway bars to dial out the oversteer (because that front end has huge grip with a 255 up front). I repeat, don't do this unless you have adjustable sway bars or it will drive like a drift car.