T speed rated tires was the O.E. rating on the 2006 Fusion SE...I used to sell tires and have been to Michelins tire plant in South Carolina twice...they make a damn fine tire...but back to your question...when you put higher (or lower for that matter) speed rated tires than O.E., you will change the handling characteristics of the vehicle at lower speeds as well as the listed "limit" of the tire....a car will handle, ride, corner, and brake quite differently when you deviate from the OE speed recommendation...sometimes for the better, sometimes for the worse...since my car (since traded) had T speed rated tires on it and I was satisfied with the performance....I wanted to stay in that range, hence why I didn't get the Firestones.