RCW 46.37.570: Odometers—Selling, advertising, using, or installing device registering false mileage.

It shall be unlawful for any person to advertise for sale, to sell, to use, or to install on any part of a motor vehicle or on an odometer in a motor vehicle any device which causes the odometer to register any mileage other than the true mileage driven. For the purposes of this section the true mileage driven is that driven by the car as registered by the odometer within the manufacturer's designed tolerance.