The Idaho National Engineering Laboratory (INEL) evaluates EV propulsion systems and components for the U. S. Department of Energy (DOE) Electric and Hybrid Vehicle (EHV) Program. This paper describes an INEL study which compares the exterior and interior acoustic noise levels of an electric vehicle to its internal combustion engine (ICE) counterpart base vehicle, under various operating conditions.
The electric vehicle was a converted 1988 Ford Escort station wagon, retrofitted with a DC electric powertrain developed by Soleq Corporation. A comparably-equipped gasoline-fueled ICE-powered Ford Escort station wagon provided the baseline acoustic noise levels with which to compare the electric vehicle. Measurements of the interior and exterior noise levels were obtained using a Bruel and Kjaer (B&K) Type 2231 Modular Precision Sound Level Meter. The tests were conducted in accordance with applicable Society of Automotive Engineer's (SAE) standard practices (1, 2, 3, 4, 5, 6, 7 and 8)* at Chrysler's Arizona Proving Grounds in Wittmann, Arizona.
The results indicate that radiated interior and exterior acoustic noise levels of the electric vehicle were noticeably quieter under acceleration and idle conditions. However, under constant speed operation the electric and the ICE exhibited essentially equivalent interior and exterior noise levels.