even though the tire width is roughly the same, you're pushing the wheel 13mm closer to the fender with a +17 offset versus your current +30. you'll be even closer to the fender if your new rim width is wider than your current wheel.

like others have mentioned, you'll probably be fine with a +17 offset and 275/285 tire. its not that aggressive of a setup. however, you can build in some more room by either rolling your fenders or running more camber.

 

yeah, there's a big difference between +30 and +17.
don't forget 285/30 won't be as stretched as 275/35 so there's more chance of rubbing.

 

crap, I never knew the offset pushes the wheels closer to the fenders... i always thought the smaller the offsets, the more concave the spokes are to the rotors.

 

I thought the front fenders come pre-rolled from the factory? So how do you roll the front fenders?

 

I'm gonna say you will rub pretty badly with 275 given your 10.5" and 17mm offset. I'm dropped 1.5" and run 285 with 10" and 25mm offset and I rub, however you can put some really (-) camber to make them fit but I would roll first. BTW offset numbers changes depending on the rim's width. Your 10.5" +17mm compared to my 10" +25mm sticks 14mm out more than mine not just 8mm.