I agree with SRK, as my GS4 also came from the factory with turmoline 17" rims (or whatever they're called) and Bridgestone tires. I have since had Dunlop, Michelins, Kumho's, Toyo's, and Hankooks. All nice tires, all ride well. I really like the Michelins, but a little pricey for me. The Kumho's were a good all-weather tire, and lasted about 30K miles. I have Hankooks on it now, rides really, really nice, and they're not too expensive. (approx $125.00/tire) Good luck..............
Spaseman