The National Highway Traffic Safety Administration (NHTSA) is investigating the pros and cons of replacing conventional rear- and side-view mirrors with camera monitoring systems on passenger vehicles. NHTSA asked for experts, opinions, and research on the implications of making this change to passenger vehicles. On the one side, automotive designers and engineers say that getting rid of exterior mirrors would improve not only the aesthetics of automobiles but reduce their aerodynamic resistance as well. Scott Miller, Director of Global CO2 Strategy, Energy, Mass and Aerodynamics for General Motors, says that exterior mirrors create aerodynamic drag while the vehicle is moving and removing them could produce a 1.5 to 2 miles per gallon gain. This is because according to Miller, 1 mpg in fuel efficiency is gained per 12-count reduction in drag and he expects a 20-count drag reduction per vehicle from the removal of two exterior mirrors. Further, a book published by SAE International notes that exterior side-view mirrors constitute anywhere from 2-7% of a vehicle’s total drag.
Two supporters of this initiative – the Alliance of Automobile Manufacturers (AAM) and Tesla – asked NHTSA to permit the installment and use of camera monitoring systems in vehicles instead of traditional mirrors. The foundational premises behind this petition are improved fuel efficiency and side vision; however, NHTSA did not grant them permission. NHTSA withheld approval in part due to a test it ran on a prototype camera monitoring system. While they found that the system proved “generally usable,” the test highlighted certain problem areas, including distorted images and problems in the rain. In other words, the test brought to light certain safety risks that could result from the implementation of cameras instead of mirrors. Therefore, before giving approval for camera monitoring systems on passenger vehicles, NHTSA seeks to further investigate the results of making such a change.
Taken from: www.sae.org