Recommended car weights

What are the recommended weights for 1:20.3 cars. Is there a difference between what a box car or a flat car or caboose should weigh to ensure the best performance on a garden RR?

Most GR people seam to just let the heavy metal wheel sets take care of the weighting of cars. Some do however add wieght to flatcars to get them to track better. Others add weight to locomotive to increase the traction effort. I do not know of ever seeing posted weights. You may need to do scale conversion to weight ratio calculations to get true weight.

I agree with Matt…Metal wheels is all I do.