I took the time earlier this week to test fit some of the wheels that I have for fitment on my 2011 Elantra-Touring (I30CW). I test fitted my winter wheels/tires. And I also have a set of Mazda RX7 16x8 ET50 wheels, and to my pleasant suprise, they fit quite nicely on the Hyundai. The centerbore is the same as the Hyundai, and there is still a fat finger width between the inside rim and the strut. At about 15 pounds, there are vey few aftermarket wheels in this size that are lighter--it is a fantastic performace option. According to my math, compared to the OE 17x7 ET55 wheels, the 16x8 ET 50 wheels will be 8mm closer to strut and about 18mm wider to the outside (the extra 1" of width is 26mm, but because it has a bit more offset more of the width goes towards the outside; if the offset is the same it would be a 13mm/13mm split...).

I am certain that a 225/50-16 will fit very nicely and will be very square on that wheel...and perhaps a 245/45-16 will just fit as well, for a bit more aggressive look.