Wyo. Stat. § 31-16-122: Selling, advertising, using or installing device which causes other than true mileage to be registered.

No person shall advertise for sale, sell, use or install on any part of a vehicle or on an odometer in a 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 vehicle as registered by the odometer within the manufacturer's designed tolerance.