Windshield defrosting and defogging systems.
S1. Scope. This standard specifies requirements for windshield defrosting and defogging systems.
S2. Application. This standard applies to passenger cars, multipurpose passenger vehicles, trucks, and buses.
S3. Definitions. Road load means the power output required to move a given motor vehicle at curb weight plus 180 kilograms on level, clean, dry, smooth portland cement concrete pavement (or other surface with equivalent coefficient of surface friction) at a specified speed through still air at 20 degrees Celsius, and standard barometric pressure (101.3 kilopascals) and includes driveline friction, rolling friction, and air resistance.
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（law school...https://www.law.cornell.edu/cfr/text/49/571.103 ）
