Passenger Car Noise Control Measures and Their Effects on Fuel Economy, Weight and Cost

Various passenger car practical noise control measures are presented and discussed. Emphasis is placed on the noise control tradeoffs with fuel economy and weight. Both diesel and gasoline powered automobiles were considered. The diesel was of the indirect injection type and a conventional spark ignition engine constituted the gasoline powered type. The baseline vehicle maintained throughout the analysis was a 2750 lb inertia weight passenger car (2400 lb, 1100 kg kerb weight). Major findings are summarised for five noise control measures considered to be most likely incorporated into future vehicles. They include: a) reduced engine speed by 10 percent, b) engine sizing and configuration, c) combustion process, d) engine structures, shielding and enclosures, and e) gas flow. Summaries for each noise control measure contain data on achievable noise reductions, and the corresponding change in fuel economy, vehicle weight and cost. Emission levels were referenced mainly to the 1979 Federal Light Duty Vehicle Emission Standards but some consideration was also given where relevant to the proposed 1981 Standards. The proposed particulate emission regulations were also considered. Noise measurements were referenced to a current high engine speed, full load drive-by test procedure (e.g. SAE J986b or similar European procedures, 70/157 EEC).