Remember that there's an advantage for cars to be light. The engine is what powers them, and so they want light bodies in order to get better acceleration and braking. On a coaster train, weight is better. The heavier the train, the harder it is to slow down throughout the ride. Since the inertia increases with weight, the wind and friction from the rails will not slow it down as much through the course. Of course, since it's powered by gravity, the acceleration will be the same, except for wind resistance...thus it's still better to have a heavier train to combat that.
With MF, speed is exceedingly important. I wouldn't be surprised if there were giant steel blocks on the bottom of every car, just to give it extra weight. These things are designed to be heavy, so 3.1 tons each, while heavy, isn't all that odd considering the design requirements.
Jman
*** This post was edited by Jman on 6/7/2001. ***