I recently purchased 6 new Hankook tires to replace the Michelin tires on my 33' Holiday Rambler that aged out. On the trip home( 25 miles on secondary roads) they seemed to have a harsher ride than ...
It's my experience that most new tires will feel like they ride a little rougher than the old ones just because one's become used to driving on the worn (and thus smoother) tread of those replaced.