Why is a 97 or 98 BMW m3 sedan faster then the coupe model of the same year?

I was just curious because all the car stat sites ive been to say that the sedan does 0-60 in about 5.5 seconds and the coupe only does it in 6.2 sec. I thought the engines were the same, but I may be wrong. If someone could tell me why, that would be great. I am just curious.Why is a 97 or 98 BMW m3 sedan faster then the coupe model of the same year?most coupes are heavier than sedan's and are lower to the ground and hug the ground betta than sedans,,,the coupes handle betta on turns and manuvering,,,maybe on-road can tell a differnt story,,,Why is a 97 or 98 BMW m3 sedan faster then the coupe model of the same year?probably weight. or maybe you saw the convertible times.