I kind of shy away from these questions because there are definitions of Mara and Tera, but they don't get followed. Tera has to do with tensile strength vs diameter and Mara has to do with weight per length. As far a gutterman goes. Mara 40 is a different horse than Tera 40, why? I really have no clue. I don't know how to compare them since they aren't actually labeled according to normal conventions.
--If a cow laughs hard, does milk come out its nose?