The weight of a machine is how much the machine weighs (in kilograms). While it appears to be just a trivial stat, trends show that machines that are heavier have better body ratings due to their bulkiness and also have some of the highest top speeds in the game. However, this is sacrificed for a lack of Grip and Acceleration due to its bulkiness being difficult to maneuver (Samurai Goroh's Fire Stingray and Black Shadow's Black Bull are two main examples of this.) Contrarily, machines with lighter weights often have better grip and acceleration, but have lower top speed and are rather frail due to the lack of bulk on the machine. However, these are just trends and aren't always followed completely (Rick Wheeler's Dragon Bird, for example, has a B in every stat despite weighing in at a relatively heavy 1850 kg). Weight also determines the recoil you get for bumping to another vehicle; the lighter party takes more damage and has a bigger recoil.