Fitting Grand Vitara wheels is a no no, these are not strong enough for your vehicle, these could easily crack and disintegrate when off road, or under emergency conditions such as emergency braking or swerving.

Everything else has been covered in the other posts.

I agree with Nev but would add that adding 16" will affect the speedo readings unless you have it re calibrated or copensate by using more expensive low profile tyres which will defeat the object and probably ruin the off road capability of the vehicle.

OLDMINIMAN

I wouldn't bother. There is a larger selection of tyres at 15" anyway. I'd only even think about it if you are planning to do a super high lift, in order to have slightly less side wall to flex about on the road. But on a fairly standard car, I really wouldn't bother. But as with all these things, if you like them, there really is no 'right' answer. The only thing I might investigat first is if your insurer will charge a rather hefty bit of wedge if you add these non standard alloys?...

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.