different size rim/tyres make it more difficult to tune your car handling wise and can even interfer with your car's traction control and other electronic handling aid systems...
but once the overall height of the rim/tyre is kept within about ~2% of stock height, everything should be ok...
what about vehicles that come with wheels in staggered sizes eg some bmw evolution the y come stoc with wider rims and tires at the rear thqan the front
what about vehicles that come with wheels in staggered sizes eg some bmw evolution the y come stoc with wider rims and tires at the rear thqan the front
hoss you saw a bmw evoloution dread? 
that must be REAL FAST dread 
