Four Wheel Drive name in 1910. Besserdich and Zachow's patented full time four wheel drive system combined a lockable center differential with double-Y constant velocity universal joints for steering. In modern terms the Battleship would be considered All Wheel Drive as all FWD products featured full-time four wheel drive with a lockable center differential. The success of the four-wheel drive in early military tests prompted the company to switch from cars to trucks. In 1916 the U.S. Army ordered 147 Model B three ton trucks for the Pancho Villa Expedition. The U.S. Army ordered 15,000 FWD Model B three ton trucks as the
Four-wheel drive (IWD)" is used to describe electric vehicles with each wheel being driven by its own electric motor. This system essentially has inherent characteristics that would be generally attributed to four-wheel drive systems like the distribution of the available torque to the wheels. However, because of the inherent characteristics of electric motors, torque can be negative, as seen in the Rimac Concept One and SLS AMG Electric. This can have drastic effects, as in better handling in tight corners. The term "IWD" can refer to a vehicle with any number of wheels. For example, the Mars rovers are 6-wheel IWD. Per