Tire options for the GXP have been limited to the Original Equipment sizes due to the unique wider front tire set-up. Many drive the vehicle in winter conditions and need a better option than the factory Max Performance Summer tires. I'd recommend taking a look at these three all-season options currently offered in the Original Equipment sizes:
Bridgestone Potenza RE960 AS Pole Position
Yokohama AVID ENVigor (W)
Kumho Ecsta LX Platinum
Read test comparisons and consumer reviews and see pricing information to help in choosing which tire will work best for you.