The automotive component manufacturers of electronic equipment have been touting the virtues of vehicle multiplexing for years. Some articles are illustrated with dramatic pictures of the amount of wire that can be saved by multiplexing. However, the domestic vehicle manufacturers have not endorsed these concepts. Why not?A comprehensive study of the vehicle multiplexing situation has now been completed and this paper addresses the real cost savings and reliability impact of wire multiplexing. Fusing aspects and vehicle wiring changes are also addressed. A revolutionary Vehicle Data Communication Network, and the required interface to make it a reality, are also described in this paper.There is a dedicated SAE activity to establish an industry standard for a vehicle multiplex network. This work has the energetic support of the whole automobile industry and is particularly viewed as a necessity for diagnostic purposes. A vehicle multiplexing standard would promote the design of a common type of diagnostic equipment to improve the servicing of all network vehicle electronics. Chrysler Corporation is an avid supporter of this philosophy and has made a proposal to this SAE Multiplex Subcommittee to use the protocol described within this paper as the Data Communications Network Standard.