The tires break loose in wet weather. the hankook optimo h426 tires, standard on this car are rated #41 of 42 available tires for this car (see tirerack.com tests). kia has put the worst tires available on their top line car! they have absolutely no grip in wet weather. they may work with the 6 cyl engine but are worthless with the v8 engine. i have had them break loose once in straight line acceleration and twice while turning corners in the first 1500 miles. kia was no help so i have ordered high quality replacement tires on my own.